I think you’re on to something, mate.
Beware the catch phrases. They don’t all deserve to be repeated as much as they are.
Personally, it’s much like what @stranger_in_a_strange_land said, for me too. I also had bad luck with the gene lottery in much the same way.
The only way to get over this sort of thing is not to accept yourself the way you are, and to resolve to become a better person. Putting off “being yourself”, so to speak, until you’re the sort of self that you could be happy to be.
Although the sort of people I think you could call “nasty” are also people who care bugger all about “being themselves” or not. I’m thinking of the sort of people for whom prisons were invented.
But for well-intentioned people with, um, a lot of room for improvement, I think you’re right.