If there's something about someone you don't like...

Mine said that to me. I says it's him I don't like. That foxed him. He suffers from delusions of grandeur imo.

i agree with that
i've noticed it

that person represents a part of yourself that you aren't comfortable with

What if someone has wronged you nick? It could be someone you previously liked but no longer do which does question the psychology no?

Bunkum nonsense.

The psychology-psychiatry mob haven't got a scooby doo about the brain/mind and what it is to be human.

99% of them are complete bluffers and guessers

Of course.  If, say, you're being bullied at work, you're probably going to take an intense dislike to that person whether you yourself possess that trait or not.

Clearly, the statement in my OP (bm put it better than me) isn't always the case but when I was passed this nugget, it certainly gave me food for thought.

That doesn’t make sense

For that to be true likeable characteristics would have to become unlikeable just because you shared that characteristic