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 am gonna be honest with you here. Some of us born with a gift, given directly from god. They can sleep, without thinking embarrassing memories, without using any medicine, without finding comfort itself. But you and I… and many others… we are not welcomed to this dream world of easy sleepers. We are not gifted.