When you were a kid you knew a guy who could hold in a fart, pretend to swallow air, then let the fart out. There are about 25 feet of intestine, the peristalsis of which is entirely out of conscious control, let alone control good enough to cause a bubble of air to pass along it from one end to the other in the time it would take to make this trick seem real.
I can both roll and curl my tongue.
And, yes, I am happily paired for life.