What happened to John before Arkham?
It's been a while since I played Batman: TEW so my memory of the game is a bit hazy, sorry if I didn't remember some story details.
At one point in Episode 3 of S2 we get the chance to ask John about his green hair to which he replies he doesn't anything about his past before Arkham. That made me curious. Most Jokers aren't willing to reveal their past because part of their goal is to prove that anyone can become like them. John just doesn't remember why he got to that point. Has there been any theories posted here as to why he got to Arkham? ACE chemicals is visited at the vigilante route, did he suffer a similar fate to the Joker in TKJ? Was he another victim of the experiments performed at Arkham?(I know that might not work timeline wise)
Any speculation on this?