It's not that I like to stay up late. It's just that my body won't give in to sleep until total exhaustion. So I go to sleep à 3-4 am and wake up at 6 still sore and tired. I do that for a couple of weeks and then when I start hallucinating I do a sleeping cure and sleep 14 to 17 hours straight. Then Rince and repeat.
Insomnia...Is not fun (my record is 58 hours straight without sleeping... most of that time was spent drawing)