[stormdennis]

My daughter has always needed her sleep, ever since she was a tot she'd get incredibly ratty and would be out of sorts the next day if she didn't get her full eight hours of undisturbed sleep. I on the other hand have always been able to get away with only a short night's sleep even staying up all night when necessary. My totally subjective opinion is that you only have so many awake hours in your life and I'm running through my ration more quickly and will have a shorter lifespan as a result

[Cthulhu_]

Everyone's different like that. I do 6-7 hours of sleep a night which is not ideal but a stable enough middle ground. I get 'stressed' (best word I can think of) if I don't get enough sleep, or more of a worry that I haven't gotten enough sleep. We tend to catch up in the weekends though.

[orzig]

That is an interesting analog to the stylized fact that all mammalian species get about the same number of heartbeats in their life. Mice have a high BPM and short life, whales the opposite