I, too, have to stay up uber late until I literally can't keep my eyes open anymore in order to fall asleep easily. Otherwise, I have to switch from my right side to my left side to my tummy to my back, switch the way my head is turned, sprawl out or sleep near enough like a mummy...It's horrible.

I'm a light sleeper because when I was a baby, my mom made sure the house was absolutely noise free when I was asleep because I was always sick, so I needed to rest.