I woke up at 7pm today. Tomorrow I'll probably get up at 9pm. Around this time next week, I'll be waking up at 7am.
This is normal for me. I have a rare-ish circadian rhythm disorder known as #Non24. My sleep cycle doesn't track with the sun. It's not at all rare amongst people who are blind, but it's rare amongst sighted people.
I also suspect it's actually more common than believed & there are people out there reputed to be lazy, immature, or erratic when they just can't sleep normally.
I recently stumbled upon an excellent depiction of DSPD in an episode of a series called "Modern Love". Specifically: S2 E2 - "The Night Girl Finds a Day Boy".
The series is excellent for many reasons. Each episode is a short-form vignette. The vignettes show lots of diversity, and "S1 E3" includes an accurate depiction of bipolar disorder.