I had the same experience learning to unicycle in my late thirties. Fall, try again, repeat. It's hard to actually get hurt (the unicycle just slips from under your butt and you end up more or less standing) and if you persevere you'll reach the great moment in which you can actually ride the thing... first a coupe of meters, then 5 or 10 from time to time, then you don't know how but you are actually able to ride it. But it still feels it should be a physical impossibility, and I still feel happy and exhilarated when I do it.