1) Official paperwork, especially if it's the sort where a trivial error can be a major hassle, like tax forms. I have some fairly serious Ugh Fields around the latter.

2) I obsess over previous mistakes, even ones that were made months or years ago. I even obsess over hypothetical mistakes, where I could have screwed something up if I'd been a trifle less lucky or if my synapses had fired a little differently. The mental monologue in the first case runs something like goddamnit, I'm supposed to be better than that. In the second case it's more of an abject horror at what Could Have Happened.