You are buried in a coffin 6ft deep, with no light or cell phone. There is only a small tube connected to the coffin from outside that allows you to breathe (edit: you can breathe with no difficulty). After 48 hours, you are dug up and given 1 million dollars. Do you do it?
Edit: No food and water, no diaper, and no contact with the outside world. Once buried, they leave for 48hr and come back to dig you up. The coffin is only wide enough for you to lay on your back (no rolling around), and the inside is wood and not particularly comfortable. The only items you're allowed to bring with you are life sustaining medication (e.g. an asthma inhaler). No knocking yourself out with pills or anxiety meds. The money is a briefcase full of cash.
I think you are trivializing it a bit. Just try lying in your bed on your back for 24 hours without turning and you would realize this is not going to be comfortable at all. Add to that the complete inability to tell how much time has passed and you may start to lose your shit. I would probably start to believe that I had been forgotten because my sense of time would be way off.