Sleep is my kryptonite. Or the lack of it. I get goofy and babble from lack of sleep. I hate it.While I was working on my doctorate...and for at least a year after that...I slept about 3.5 hours each night, with a 90 minute nap in the afternoon. Built into my schedule was about 2 hours with family and about 4 hours a week for friends/special events.