I've been thinking about it.. and I think I understand most of them...

Being around people who are drunk... (my dad was a drunk who beat his wife).

Being alone in a strange place (I was sexually abused in a stranger's home)- I had one experience of absolute dread when I spent the night alone in a strange hotel room.

Being around people who are arguing (my parents had some epic fights).

Being around people who are yelling in anger (see above)

Even petty little controversies in social groups bother me.