> Why do even grown men sometimes miss the bowl and pee on the floor when they're standing up?
From my experience of living with male roommates - this can happen when they are drunk.
As for keeping the toilet seat down I can't understand men either. What is the difference where to pee? If you are accurate enough you won't spoil both the toilet and the seat, if you are not - you'll have to clean in any case (or the toilet, or the seat).
So I think toilets should be once and for all made with unmovable seats ;)))