I have never been able to get up, although i have had Myasthenia gravis all my life. i feel like i could have 16 hours sleep still would not be enough, although i can still get through the day on 4 hours sleep. Funiest thing though is my alarm wakes my wife, and son and usually my neigbours but i still sleep through it and swear blind my wife turns it off. Once she went on holiday with her parents and i was late for work all week lol. but i'd say i was more of a night person though but i am always feeling tired.