One very fresh story (less than 15 minutes old) about the topic:
Twenty something players left, ten prizes. I'm in CO, holding 77, have a pretty modest stack. Everybody folds, I am going all in. Button folds, SB is thinking, I am falling asleep.
Very soon, I am waking up, only to see fourth heart falling on the river. I'm out.
I open the replayer and see that the very first card was seven. After that, besides three Queens or QQ and pair, he could beat me only if he buys four cards for a str8, or four hearts for a flush. He bought four unique cards for a Royal flush!
In a word, I overslept a major trauma. My perfectly timed sleeping has spared me from watching how they're coming, one by one.
Moral: I'm a healthier person now, because I slept when I should