History Fridge / ItsAlwaysSunnyInPhiladelphia

* So Dee's neighbor Gary was the serial killer. That explains how he knew the shears would cut though bone. The gang insists that Dee doesn't fit the victim profile, but he's clearly attracted to her. Was he just biding his time? Did she really not fit the profile well enough to murder? Did he kill all those other people ''because'' Dee was taking advantage of him?
** If you know a thing or two about real-life serial killers, the picture becomes clearer. Some serial killers—most notably Ed Kemper—need to kill surrogate victims to “build up courage”, so to speak, before killing the person they really want to kill. In Kemper’s case, he killed several female college students before finally killing his desired target, his mother. In Gary’s case...
** It's possible Gary could have been hiring his past victims to water his plants to lure them into his apartment alone. In which case, Dee's neglect of the chore might have actually saved her life.
** Given that Gary's victim profile was young blonde women, is it possible that the Waitress could've been next?

* After Country Mac's death in "Mac Day" none of his closer relatives show up to claim the body, and it's up to Mac and The Gang to handle the funeral. It's entirely possible that the reason he came to Philly in the first place is that he was disowned by his family for being gay and had to leave his home.

* "The Gang Gets Quarantined" and later episodes reveal Dee is an alcoholic. Dee was a surrogate mom for Carmen in Season 6. What are the odds that she remained sober for the entire pregnancy? Especially since her first instinct minutes after delivery is to suggest they go get beer.
* Frank's paranoia about getting arrested in "Frank Reynolds' Little Beauties" is ''much'' darker after the Season 15 subplot about Frank being involved with Jeffrey Epstein.

* "The Gang Gets Quarantined" and later episodes reveal Dee is an alcoholic. Dee was a surrogate mom for Carmen in Season 6. What are the odds that she remained sober for the entire pregnancy? Especially since her first instinct minutes after delivery is to suggest they go get beer.

* If you know a thing or two about real-life serial killers, the picture becomes clearer. Some serial killers—most notably Ed Kemper—need to kill surrogate victims to “build up courage”, so to speak, before killing the person they really want to kill. In Kemper’s case, he killed several female college students before finally killing his desired target, his mother. In Gary’s case...
* Given that Gary's victim profile was young blonde women, is it possible that the Waitress could've been next?

* After Country Mac's death in "Mac Day" none of his closer relatives show up to claim the body, and it's up to Mac and The Gang to handle the funeral. It's entirely possible that the reason he came to Philly in the first place is that he was disowned by his family for being gay and had to leave his home.

* If you know a thing or two about real-life serial killers, the picture becomes clearer. Several serial killers—most notably Ed Kemper—need to kill surrogate victims to “build up courage”, so to speak, before killing the person they really want to kill. In Kemper’s case, he killed several female college students before finally killing his desired target, his mother. In Gary’s case...

* In the season 6 premiere, Dennis tells Mac that he hasn't had feelings since he was 14 years old. Come season 11, we find out that Dennis was statutory raped by a fifty-year old librarian when he was fourteen.

* In "Sweet Dee has a Heart Attack" Charlie insists that he's got boxes of mail addressed to Pepe Sylvia and Carol in HR, neither of which actually exist. He seems to be going insane, but we know that Charlie is nearly illiterate. Pepe Sylvia = Pennsylvania and Carol in HR = Care of HR. However, this is all countered when Mac insists that everyone he's talking about really does exist. Charlie's delusion might have been an earlier draft of the script, or it might be intentionally vague as to just what is going on.
** Another interpretation is that Mac was talking in generalization; his counter is him saying along the lines of of "not only do those people exist, but they've been asking for their mail for the past few days!" in response to Charlie claim that half the people in the office don't exist, ''as if Charlie was convinced he and Mac were the only'' real ''employees,'' and his illiteracy combined with his paranoid delusions means he obsessed over the Pepe Silvia/Carol in HR case so hard that he completely neglected to do his duties in the mailroom and the people upstairs took notice.
** WordOfGod later {{Jossed}} this theory over [[https://twitter.com/sbmarder/status/281899569766354944 Twitter]] but let's be honest, it does sound ''exactly'' like something Charlie would do.

* In the season 2 episode "Dee and Dennis get a New Dad," when Frank and Barbara meet for the first time since their divorce, he makes fun of her age by saying she has a "turkey neck," and in ''Dennis and Dee's Mom is Dead'', it's revealed that she died from a "botched neck lift." It would seem that Frank's comment actually did get under her skin, making him indirectly responsible for her death.

* In "Who Got Dee Pregnant?" Dee's [[spoiler: false]] supposition that one of the gang is the baby's father takes on a bit of Fridge Humour when one realizes that Kaitlin Olson was actually pregnant at the time, and that Rob McElhenny (Mac), her husband, was the father. So technically, Dee wasn't wrong...

* "The Gang Turns Black" doesn't include any scenes in Paddy's or Charlie/Frank's apartment. All we get to see is Dee's apartment, Dennis' car from the outside, the street, the police station, a public electronics store, under a bridge and a nursing home where apparently Old Black Man actually belongs. [[spoiler: All places that Old Black Man could have seen.]]

* In "Being Frank" it's revealed that Frank has an unknown terminal illness, but it isn't treated because Frank runs out of the hospital in a hurry. In "The Gang Goes to a Water Park" Frank pretends to have AIDS in order to get onto all the rides. This culminates in him bleeding in the pool, causing everyone to think he has AIDS. After this happens, Dee, Mac, and several kids fall into the water. If Frank's terminal illness really is AIDS, all those peopel might now have it as well.

* In the season 2 episode ''Dee and Dennis get a New Dad'', when Frank and Barbara meet for the first time since their divorce, he makes fun of her age by saying she has a "turkey neck," and in ''Dennis and Dee's Mom is Dead'', it's revealed that she died from a "botched neck lift." It would seem that Frank's comment actually did get under her skin, making him indirectly responsible for her death.

* So [[spoiler: Dee's neighbor Gary]] was the serial killer. That explains [[spoiler: how he knew the shears would cut though bone]]. The gang insists that Dee doesn't fit the victim profile, but he's clearly attracted to her. Was he just biding his time? Did she really not fit the profile well enough to murder? Did he kill all those other people ''because'' Dee was taking advantage of him?
** Given that the victim profile was young blonde women, is it possible that the Waitress could've been next?
* In "Being Frank" it's revealed that Frank has an unknown terminal illness, but it isn't treated because Frank runs out of the hospital in a hurry. In "The Gang Goes to a Water Park" Frank pretends to have AIDS in order to get onto all the rides. This culminates in him bleeding in the pool, causing everyone to think he has AIDS. After this happens, Dee, Mac, and several kids fall into the water. Now, we know they don't have AIDS, but what if they now have that terminal illness Frank was diagnosed with? We don't know if it's bloodborne or not.
** [[SarcasmMode Better yet]], what if Frank really ''does'' have AIDS, and now they have it too?

* Frank's gradual {{flanderization}} over time, including his degrading physical state, are to be expected within the world of the show. In his first appearance, when he's introduced as an upper-class businessman, he makes a conscious decision to embrace the Gang's grimy, depraved lifestyle because his wife divorced him and he's been depressed to the point of suicide about losing most of his money. He was pushed into his upperclass lifestyle by his wife, but after his divorce he decides that he's more comfortable being a debauched drunk. He gets worse and worse in each season as he goes deeper and deeper into the Gang's world.
** The same could be said of ''every'' member of the Gang. Dennis's pathological narcissism and fear of losing his looks have led him to increasingly dangerous habits, including starving himself (he says that he never eats breakfast, and skips lunch most days, too), to stay youthful--habits that have only increased as he ages. Dee, who's the ButtMonkey of the bunch, has suffered years of psychological torment and perpetually fails in her attempts at acting and stand-up comedy (as seen in "The Gang Broke Dee," she's about a single setback away from giving up completely and falling into total depression). Mac suffers from intense internal conflict between his "traditional" Christian values and [[ArmoredClosetGay homosexuality]], which gradually gets harder to deny as time goes on; he also puts his body through various torments, including gaining and losing sixty pounds of fat in roughly three months. And Charlie huffs glue and eats tuna fish and cat food ''every night'' just to be able to fall asleep, and harbors an unhealthy obsession with a woman who despises him. The fact that none of them are trying to fix their problems through therapy--or even getting away from the toxic friend group--only exacerbates all of these issues. Of course they're getting worse as time passes!
** Also, "Being Frank" reveals that Frank himself has some kind of brain disease (most likely a tumor) that's going untreated, and it's badly affecting his memory and overall mental health. If the illness is progressive, it's only natural that he would degrade further and further as he ages.

* In "Sweet Dee Gets Audited" there is a debate between the characters about what to do with the corpse of a dog that is rotting in the alley behind the bar. Mac and Charlie want to perform a 'dog funeral', while Frank and Dennis want to throw the corpse in the dumpster. Mac probably supported the dog funeral because other episodes have shown that he still owns an old dog that he is emotionally attached to, so it makes sense that he wants to bury the dog with dignity. In addition, Mac is a hardcore Catholic, so it makes sense that he would place so much value on a proper burial. Alternatively, Frank has expressed the opinion that a dead body is essentially trash, to the extent that he does not care what happens to his own corpse when he dies. Dennis has expressed the opinion that eating a dog is no more morally wrong than eating a chicken.

* Re-watching "Mac Is a Serial Killer" makes you realize [[spoiler: Dennis is "getting off" at the severed heads in Gary's fridge.]]

* "Mac Day" states implicitly that every member of the gang gets their own day to decide what is done. That means there is a Charlie Day. Who plays Charlie? [[ActorAllusion Exactly]]

* During the entire series, Charlie is only seen behind the wheel of a car once, and during that instance (in "The Maureen Ponderosa Wedding Massacre") Mac comments that it's been a long time since Charlie has driven a car. Not much else is made of it, but Charlie lacking a valid driver's license would make perfect sense-- it'd be pretty hard for someone who's nigh-illiterate to study for a driving test, and it would also impair his ability to read road signs and street names.
* In "Who Got Dee Pregnant?", Mac invents the phrase "browning out", using it to describe a drunken stupor that's not quite a blackout. He gets upset that Dennis starts to use it, but Charlie argues that since Mac put it out there, the phrase is "public domain." One might not expect someone as uneducated as Charlie to know what public domain is, but Charlie is a great musician, which might be where he knows the concept of public domain from.
** It could also be one of the phrases he only vaguely understands but has adopted as part of his extensive knowledge of bird law.

* The title is ''It's Always Sunny in Philadelphia'' but the opening credits show Philadelphia's sights at night. Right from the start, you understand the irony of the title.

* In "Being Frank" it's revealed that Frank has an unknown terminal illness, but it isn't treated because Frank runs out of the hospital in a hurry. In "The Gang Goes to a Water Park" Frank pretends to have [=AIDs=] in order to get onto all the rides. This culminates in him bleeding in the pool, causing everyone to think he has [=AIDs=]. After this happens, Dee, Mac, and several kids fall into the water. Now, we know they don't have [=AIDs=], but what if they now have that terminal illness Frank was diagnosed with? We don't know if it's bloodborne or not.
** [[SarcasmMode Better yet]], what if Frank really ''does'' have [=AIDs=], and now they have it too?