If I had to guess - I would say I started on two skis in 1965. Took me an entire year, 18 tries at multiple sites with multpile training aids behind several boats before I actually got up on two skis. I was not quite 10... Skied on two for a long time, until my female cousins and my older sister all started skiing on 1. Dropped a ski for probably 2-3 years before I had the courage to try a deep water start. Failed multiple times.

Then in summer of 1971 we were at a local lake with friends. The first guy in pulled the heel off one of the combo skis (very old style bindings) and dropped it to the bottom of the lake. All that was left was the ski with the rear toe... This guy tried several attempts and failed. So Dad looks at me and says - "This boat won't get me up on one, and Thor (real name - other kids dad) doesn't ski, so if you can't get up on 1 our day is done before we start." So I jumped in, put on the ski - got up, dragging a leg - and have not looked back.