I guess it's just the way some people are wired.
Even as a kid, I liked staying up late.

I did work for many years having to show up by 7:30 or 8...also having kids to get off to school but more than once after the kids left, I went back to bed : )

Now we are old, hb is a morning person...he's up by 7 and in bed by 9 PM.
Works having to be together 24/7. I roll out around noon and up until 2-3 AM