Adults do, too. 
Glad to hear you’re mending well. I broke a limb as a kid and it healed well, but very very slowly. I live in some fear of a broken bone as I near retirement age and beyond.
Avocado pitting report:
Much to my amazement, a corkscrew does remove pits very nicely. As with a knife, the hard part is steadying the half fruit as you try to drive the screw into the apex of a slippery sphere. You have to push pretty hard to start the point into the pit’s skin. But not so hard as to damage the fruit; there’s no smooshing. Once you get the point started, the pit’s innards are soft enough that the screw screws in nicely. You only get about 1 turn in before the pit starts spinning then lifts out easily. Overall it works fine, but it feels mighty effete doing it.
I tried several different spoons and was disappointed. It’s messy and damages the fruit. My inner neatnick really likes that smooth hemispherical cavity where the pit used to be. Damaging that is anathema. The spoon technique also tends to leave a layer of fruit stuck to the pit, which is wasteful. I’m also 4 for 4 on the pit suddenly breaking loose and rolling across the kitchen floor leaving a snail trail of green slime I have to wipe up. Bottom line: safe but stupid.
I think I’ll be doing the corkscrew a couple more times before deciding between it and the knife for my preferred technique.
AFAIK the ethylene trick won’t work. Mostly because the innards aren’t that permeable. The challenge is to get the center ripe enough without over-ripening the outside. I believe ethylene would make that worse, not better.