Cool. Now do the same thing 6 more times, without resurfacing.
If he can do it for two months straight around the clock without snapping, my money would be on him doing two years too if he had to/wanted to. Elizabeth Fritzl did 24 years trapped in a cell in the basement, eventually no matter how bad the situation is it eventually just is. Same goes for people with severe disabilities and such, if I ended up in a wheelchair I'd get very depressed right away. But if I live through that first phase I don't see myself saying I've lived a year in a wheelchair but a year and a day is too much. I'd either have found a reason to live - or not - long before that.