Ode to: DANGIT MY FOOT JUST FELL ASLEEP!!!!

It's happened to every one... You're just sitting there innocently and all the sudden when you try to sit up your leg is pretty much jelly and before you know it, you're on the ground and your foot has that pins and needles feeling.  *Grumble*  I challenge you to figure out why our feet fall asleep...  Cuz I have no clue.