In Chapter 1 when Clark is moving in New York, he saddened by the fact that he wasn't there during the Chituari invasion in 2012. While a reader might be confused about the fact that he wasn't there (due to his Super Hearing, Super Speed and Flight) it is possible because Clark was probably suppressing his powers during his worldwide journey to discover himself and so he can learn about the world much as regular humans do.
Alternatively, he could have been taking in data in the Kryptonian scoutship and learning more about the wider universe, being so concerned with learning about the past that he wasn't paying attention to events in the present.
True, it would be cool if the author referenced that in the story.
