Strike a Nerve
My wife is a therapist at the state correctional facility. The only thing for her that makes her judge someone is if they strike a nerve, usually because they remind her of an insecurity she has had to deal with in her own life.
For example, one client, an addict, spouted off about how the whole world was against him and he did nothing wrong. He started bragging, going on about all the amazing things he was going to do when he got out of the clink, and his whole attitude really rubbed her wrong.
As she was telling me about the guy and how much she had trouble with him, I was like, “He sounds just like your brother.” Not to go into it, but her brother was not a great guy. After that, she realized why the client triggered her so much. Story credit: Reddit / legitimate_salvage