Have you ever been in a situation with a group of people where you feel that one of that group is very stupid?
Forgetting momentarily that you think that that person is stupid, you light-heartedly repeat something that they said, with no malice intended?
Someone says 'that's a really stupid thing to say...'?
Looks are exchanged, and you know that everybody else thinks that person stupid, but everyone is too polite to say?
It's funny, I really don't like the stupid person. Ask me why, I have to shrug and say, I don't like them. If I tried to give a reason, it would make it seem that they were a bad person, or, at least, to blame. They're not. I just don't like them.
I just don't know whether my dislike is based on their stupidity, or whether I am contemptuous of their stupidity because I don't like them