I pretty much break out in hives when I am late to an appointment of any type. I don't actually break out in hives just from being late, at least not most of the time. Still, my wife will tell you, her voice weary with years of my punctuality neuroses, that I am almost obsessive about keeping my obligations once they have a specific time and place associated with them on my calendar, no matter how odious that task becomes. She also might add that my skin gets bumpy if I actually miss a commitment entirely.
The obligation I will head off to in a few moments isn't as odious as some that I have honored over the years, but it's one I'm not much in the mood for right now. I'll still go and do it, though, because I'd be far more miserable if I didn't. There's not a particularly rational reason for me to meet this particular commitment with the fidelity I bring to it. Lord knows I don't bring similar devotion to other aspects of my life. I keep my calendar, though.
In the real world of day job, my neurotic insistence to show up when and where I said I would, no matter what, hasn't made me independently wealthy--but it has kept me in work over the years. I've learned the hard way that I have to manage my compulsion by not overcommitting myself. The times I've over-subscribed myself have been unpleasant ways to learn that lesson.
I've never met a successful person who wasn't a little bit neurotic in exactly the way that made them successful. I sometimes wish my particular neurosis was more valuable than punctuality, but compulsive habits are hard to cultivate in yourself. I'll have to stick with what I've got. At least mine isn't debilitating.
Sorry, I've got to go now.