I lost so much of my early teenage years to sleepovers where we'd stay up all night playing Goldeneye and Perfect Dark. Good times.
I might say the same thing, if "sleepover" didn't imply sleeping.
Well, sleep was very rarely involved. Usually it was stay up all night, go home about 11am, pass-out for a few hours then wake up and get lectured at by the parents for being irresponsible.