Some people actually are short-sleepers naturally. He might be one of them. Or he might just be perpetually exhausted to the point where he's learned to "functi

Some people actually are short-sleepers naturally. He might be one of them. Or he might just be perpetually exhausted to the point where he's learned to "function" on less sleep. Speaking from personal experience, you can get used to 4-5 hours a night and think you're okay. Starting getting north of 7 and you will notice a difference after a week. (Unless you're a short sleeper, I suppose they just can't sleep that much.)