Humm, well considering I started this I should say mine too. When I was making my de_bedroom, because I was so excited with how cool it was turning out, I mapped for about 5 hours . lol that doesnt sound like much compared to other people but after that I felt preety damn bored and depressed (I have no idea why, I must be screwed up).
At this one cyber cafe near us they have alot of really hard core half life / counterstrike people, and every once and a while these guru's have a mapping party or something like that where they stay up all night mapping :