Or, for a slightly less doomsday scenario, just a relatively simple problem affecting one person, but they're still trusting you to figure it out, and they're expecting you to do it sooner than later.
There's a point at which the fun really starts to go out of that. I've always been a bit of an adrenaline junkie, I've always worked well under pressure, but nowadays my favorite thing is quiet time in the sunshine digging about in the garden. (Oh god, that makes me sound old.)
Maybe this will never happen to you. I hope not! But I've been thinking a lot about what Chuck said, and about my frustrations with technology, and I think that maybe this has a lot to do with it.