The other night I slept at a normal time, went to bed at 10pm, and slept till 7am.. But by 9am I was ready to pass out again and slept till 4 in the afternoon! If I wake up in the morning, no matter how many hours sleep I got, I'll feel tired for a very long time. If I got the same amount of sleep but woke up in the after noon or evening, I'll be full of energy..

It makes no sense to me at all and it's something that has been bothering me for a very, very long time.