'The Invisible Man'

My main question is this: Why is the Invisible Man so pissed off? Initially, I thought it was because he was invisible and had to wear fake noses and all these clothes.

But then you delve into his past and you realize he was kind of an asshole before he was invisible.

Then he gets into his brain that he's going to have a reign of terror ... all the while we assume he's trying to find an antidote for his invisibleness.

Why couldn't he be happy with sneaking in girls' lockerrooms and stealing stuff?

Some people just don't know what to do when fate deals you a good hand.