I can see Crusty running to the teacher/yard monitor/his mother/your mother/etc... every time you didn't want to deal with his bullshit, so you got lectured, and I guarantee that afterwards Greeee would say "See, I told you that you have to do it how I say!" in his unique slurpy, drooly way. That's when you just want to punch him in the face and keep punching until they have to re-arrange his face (which would likely be an improvement) but you know you can't because you'd really get in trouble for pounding the retarded kid. So, eventually, everyone learned to hate him, excluded him from absolutely everything possible, and treated him like a leper. The problem is, Crusty took it that it was because he had a deformity, not that he was an annoying, creepy asshole that got everyone else in trouble just because they didn't want to do things the retarded kids way. As a result he turned into an adult who acted just like he did as a kid.
As much as it would have smashed his retarded view of the world, it would have been for his best if someone has taken him to task and given him a complete rundown on exactly why everyone hated him, why everyone considered him a creepy ass psycho weirdo, and what he could do to unfuck himself if he ever wanted to stop being treated like that. Unfortunately, no one ever apparently did that for him, and it is way, way too late for him now. So, he'll just be a permanently retarded adult who ends up dead in a ditch somewhere, completely broke, and as nothing more than a drooly punchline to a joke about whores.