Has it ever occurred to you that maybe you’re atypical in this way? I’ve done flights from the US to Europe, and not slept during the flight and landed in the morning in Europe. While I’m initially tired, I’m unable to fall asleep in this situation. I spend the day walking around outside and eating at local time. After going to bed just a little earlier (wall time) than usual the first day, I’m adjusted because of the sun (aka the number on the wall), food intake, etc.

It's not just the GP. I've done both US Eastern to EU and US Eastern to US Pacific enough times to know how I respond.

I find the 3 hour difference to the west coast to be way harder to adjust to than the 5 or 6 hour (depending on destination) difference to Europe. I'm a zombie for a week going to California and spring right back to eastern time going home.

Going to Europe, it's about a day to fully kick over to the time change in either direction. Admittedly, it's a rough day headed east that usually involves an afternoon nap, but I've come to despise the three hour change to Pacific time far more.

That's a red eye you're talking about though. Yes, I normally try to fight through the day and go to sleep at a normalish time for the location. And I'm usually on a decent schedule within a day or two.

But if I take a short trip from the East Coast to the West Coast in the US, I often go to bed on the early side and wake up early.

Many studies claim the response people have to the manipulation of light intensity, color, and duration, does effect several aspects of the person. Sleep hygiene does seem to play a large role, but the sun is likely the largest contributor to the human body's roughly 24 hour circadian rhythm.

Ironically it's the wavelengths at sunrise which have the greatest affect. If teenagers are sleeping in they don't get to see these:

> Researchers said the wavelengths at sunrise and sunset have the biggest impact to brain centers that regulate our circadian clock and our mood and alertness.

https://www.sciencedaily.com/releases/2020/02/200220141731.h...

The sun determines my sleep hygiene.

Absolutely not my experience at all. Something as simple as the sun rising up sooner in summer makes me inclined to wake up and be active earlier, whereas winter makes me feel groggy and mediocre for several hours until the sun is actually up.