i operate on 6 a day everyday. i can still work well on 5, but not for a long period of time. if im in a bind i can go with 4 hours, but ill be yawning and stuff. i cant sleep more than 8 hours, and if i do sleep for 8 hours im so jittery i cant really commit to tasks very well. not sure why, family always told me i was just a hyper person. they also said it would subside as i got older, and at 37 it hasnt really changed much. i dont get sick very often at all either, which a lot of people told me i would be sick often with my sleep habits.