I ask exactly because I can't sleep longer then 7 hours and 4 hours can be enough for me. Yes, we do exist.
This night I have sleept only for five and half hours and I feel just fine.
As I've said it before, 7 hours is just upper border, not standard .
Form what I have experienced people treat this like supernatural power.
Why they do that, I don't know.
I also don't know how it is possible but it works for me.
Form what I have experienced the more you sleep the more tired you will be.
But if I have to guess why am I like this I would say that the way of life and how I use my brainy are the reasons why this works for me.