I only really care if it's inconveniencing me personally. If it's a group project, I'd be livid; hanging out with friends, I don't really care unless it's some kind of activity that we're now having to wait on them for. Even then, I've got a good half hour window before I'm genuinely annoyed.

I'm pretty punctual, after growing up with a mom who got me everywhere late until I was old enough to take the bus. That was frustrating as hell, but it also left me with some empathy-- I could see she wasn't doing it on purpose, and I figured out really quickly that it was something she loathed about herself. It's really weird to see. You'd think after decades, she would have some grasp on how long it takes her to get ready to leave the house, but time doesn't seem to pass the same way for her as it does for normal people. I've sort of resigned myself to it at this point; I just tell her to be everywhere fifteen minutes before she needs to be there (but then I feel bad when she shows up just on time for the real start, all hysterical and miserable and apologetic about being late).