Yes, you went through the same shift on circadian rhythm that most people do as they age. Babies sleep a lot irregularly. Very small children take a nap in the middle of the day. Young adults are sleepy sometime between 1-4am. Adults stay up 9pm-maybe 1 am. Old people sleep little and wake lots, somewhat like babies. There are predictable shifts on average in preferences that have next to nothing to do with what we do.