Oh, I learned it very early in my "career" ... soon after I figured out the initial maneuver...maybe 14. Geeze, then you could "only" do it 4 or 5 times a day....had to find a way to make it last, so edging was it.......
One of the things I liked to do as a teenager was if given the opportunity, to see how long I could keep an erection. Not quite the same though.