I can fall asleep almost anywhere. I routinely fall asleep in the break room at work. Once, I was helping a friend fix his car, and I fell asleep on his garage floor when he went inside to get water.
But in a hot metal tube tearing through the sky, with my neck all kinked? Get out of here, man.
I actually find it easier to fall a sleep on a plane - not that I have any issues anywhere else 😁 but as soon as I get on that plane, you bet I’m gonna get some zzz time. Even if its just a 2hr flight