10 Worst Things Batman Has Ever Done
8. Mind-Wiped Robin And Sent Him Back To The Orphanage
DC comics in the 50's and 60's are notorious for being completely bonkers and seemingly taking an "anything goes" approach to plots. One idea that gave them a lot of freedom was that of "imaginary stories". These were special issues featuring out of continuity stories, allowing writers to do whatever they wanted without worrying about it affecting future issues.
One such issue was The World's Finest #153. In the story, Batman became obsessed that Superman was the one who killed his parents. When Robin tried to point out how dumb that idea was, we got the memetastic panel of Batman slapping his ward across the face.
Robin still tried to stand up for Superman though. Fed up with the backchat and realising that maybe adopting a child was just for Christmas and not for life, Batman made use of his local orphanage's liberal returns policy to get rid of Dick. This was, of course, after hypnotising him to forget he ever met Bruce.
Batman later discovered that it was really Lex Luthor who had killed the Waynes for their anti-Kryptonite formula. Realising his mistake, Batman sacrificed himself to save Superman.
Batman was still enough of a jerk not to tell anyone what happened to Robin though so he was just left to be haunted by the fact that he couldn't remember months of his life.