I go to sleep somewhere around 3 or 4 am and wake up around 11 usually (earlier today because I have plans). I work second shift, so I really see no point in going to bed before midnight- that's around the time I get home and start making dinner
When I had early classes in school, I would stay awake until 3 or 4 still and wake up at 7:30 and then take a 4 hour nap before heading into work in the afternoon
I laughed at the notion of a sleep "pattern" too, bc I certainly don't have any set rules about my sleeping!
(and I can sympathize with the whole being woken up early thing- my dad wakes my sis and I up at 8 am when we're home, stating that it was nearly noon and time to get our lazy selves out of bed... at least he's cheerful about it I suppose
)