On one hand, I'm usually pretty tolerant and understanding. Sh*t happens, and I've been known for missing a deadline once or twice. Or thrice. I can wait if someone's slightly off schedule.
On the other hand, I'm self-employed, and working with a publishing company. They may tolerate a slight delay--but if I were late two weeks, more than once, I'd be in deep trouble. Sooner or later, there comes a time: either sh*t or get off the pot. Sure, I'm ADD (true)--so what? I have to give the results or loose my source of income and go beg for food at the railway station. You guys in USA should be so lucky. Other parts of the world are less forgiving.