This article emphasizes just how weird sleep is and also how personal, but I think there's far more to it than preferred sleep timing but also environment. It

This article emphasizes just how weird sleep is and also how personal, but I think there's far more to it than preferred sleep timing but also environment. It took me ages to get to sleep, unless I freecycled around the clock, until a few years ago when I realized I often easily fell asleep while other people were talking around me (think visiting family in the evening, Christmas, etc.) Since then I've put a podcast/audiobook on, earphones in, and almost every night since I'm asleep in 20 minutes. Realized I'm a verbal thinker and my brain "stops thinking" if other chatter is distracting it, whereas silence guarantees me a bad time. Now I sleep totally normal hours no problem.