I write about time management a lot. I'm also one of those comically punctual people who don't get the idea of social lateness. If you invite me to a party at 8 ... I'll probably be there at 8.
So being late to anything puts me in quite a state. I don't like to scramble when I've already made plans. So I get agitated. But what I've started to realize lately is that the agitation can be a problem in its own right.