I know I’m going against the grain here, but I actually enjoyed Batman v Superman: Dawn of Justice. It was a deeply flawed movie, but it wasn’t as bad as people want it to be.
If you have seen the movie, then you know that there are glimpse into the DCU. One of those involves a Robin suit, in a glass display case with “HAHAHA The Joke’s On You Batman” graffitied on it.
Batman V Superman director Zack Snyder sat down with IGN, to explain that scene:
“In my mind, it was that Robin had died 10 years earlier, during some run-in with a young Joker, so there was a fun backstory there to play with. I felt like the whole idea was that there had been loss and there had been sacrifice. In a weird way, he had sacrificed everything to be Batman. He doesn’t really have a life outside the cave. I thought that including Robin, a dead Robin, was helping us understand that he’s been on quite a little journey.”