You might think my ex was a sociopath, but no -- he's a normal male, working as a university professor.

My best take on what "normal" means in that sentence is "not obviously weird or dangerous, and not an especially rare type". However, it's ambiguous-- it could mean "a very high proportion of men who appear normal are that abusive".

I don't think the poster has a clear idea of what sociopath means, since one of the things many of them are good at is passing for normal.