In my early 20s and "nature" has definitely not blessed me with any productive hours of energy to forgo sleep. I attribute it all to caffeine, D3+Calcium, B12, and being in an environment where its socially normal to be heading to a coffee shop at 11:30pm or library at 1am.
No caffeine\supplements (2-4 weeks off to account for any withdrawal effects) or knowing friends who are also up late, I default to 10 hours of sleep and am also less productive.
[If you want to live an Erdos lifestyle, I imagine you can maintain late night productivity very late in life with only slight, completely-unavoidable age related decline. While this lifestyle is socially expected of college age students or the norm, it's socially discouraged and deviant for older Americans ... I think social causations should be slightly more heavily weighted than an age based causations]
You think you need a lot of sleep now. I've got news for you : it's going to get worse as you get older. Everyone has different sleep needs - but it's pretty much a given that you'll need more of it the older you get.
