Wait I want to know more what happened to the four eyes guy:(

I'm fairly certain the flashbacks belong to biker guy. Four eyed saw his memories because of the physical contact biker initiated. He cried because of them. ^^

If I were to interpret what was shown, it seems like biker guy as playing baseball when he caused an accident because of his homerun ? Not certain, but at the end it did say "it blew his head off"

that, or biker is the one who suffered the accident which damaged his face.. this actually makes more sense given his mask he could've been a passerby and not a player then.