I would feel like a BOSS! lolz.. jk.. Surely I will forget how to walk the next day cuz I have been lying down on my bed 24 hours the day b4! :P :P ..Just kidding.. :P
Depends on the reason for the "have to" part.
I get a headache.
Depends if I'm alone on the bed ;)
Then not so fun... I'd spend the time reading but after a few days I'd probably be very bored. Are you confined to your bed? :(