5 ms·

I almost had a car crash while driving to high school half asleep. Now I'm older and I get up at the same time but I don't feel tried at all.

• stephen_g 8y ago
  Glad it didn’t turn out badly, but from a sleep cycle perspective it’s normal. Kids usually have fairly early sleep cycles, and as they age it gradually gets later, peaking around late adolescence where it can be three or so hours later than an adult. After that, it shifts back to normal over the next decade or so. Aparantly this has been observed not just with humans but in various animal species as well. But there are various disorders where people either have unusually late or early sleep cycles that can be up to several hours different from normal.