Are you good at chasing friends away?

Sometimes, usually when I am in a lot of pain, I chase people away. I generally succeed, although I was unable to chase my wife away when I got sick. I don’t quite understand why I stopped chasing her off when I did. I know if I had gone one step further, she would have left me.

Anyway, if you are good at it, what makes you good at it? Why do you do it? Do you chase the right people away? How can you tell if someone is good or bad for you?