User blog comment:IHHeroes/Changes going forward after Crisis/@comment-25054842-20200116162051/@comment-25054842-20200116214350

The thing is, J'onn returned the characters memories from the Crisis. Of course he didn't return to them all the memories from the previous earth, and he doesn't need to. Because most of the things that happened to the characters before Crisis, also happened in Earth-Prime.