As You Know: The concept of the previous Super Sentai are explained to the Zyouohger by their counterparts. The 4 Zyuman they have never heard of them before (which checks out because they spent all of their lives prior to the show in Zyuland) but humans Yamato and Misao who would logically have heard about (or lived through at least half) the 39 other Earth invasions at some point simply say "Oh yeah that did happen" like it was something they'd never thought of much until then.
