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.
Hot? I’m usually cold on airplanes. That would definitely make a difference for me.
Neck pillow for the neck kinks. I don’t like the horseshoe shaped ones though, I like the trtl brand style. Expensive, but it became worth it when I took a job requiring a couple flights per month minimum.
While I’m usually also freezing on the plane I noticed that Japanese Airlines cranks up the Heat during the night.