Steff and I have decided that when you go to sleep, for longer than 2.5- 3 hours, and it's not your "man it's been a looooong ass day and i really need some sleep so i can get up tommorw and be refreshed" sleep, that's you catching up on sleep you've missed earlier in the week. So the next time your nap passes the 3 hour mark, it's no longer a nap. Spread the word!