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.
There is a good trick: Business class. As I only fly business class long haul as I only fly for the job.
And luckily I can force my clients to pay for it.
Otherwise, as a rather long and large person, I am fucked.