I'm one of the younger guys on this forum (e.g. "I have grandkids your age!" is a common comment from club members) so I come from the generation of not having had to do anything mechanical to cars.
When I bought my first Model A, I wasn't that good at driving a stickshift, so that was the first thing to learn.
Other things:
-Changing oil (never did that before)
-Navigating around a toolbox (never had to before)
-Using a torque wrench
-Polishing metal
-Electroplating
-Stripping paint (chemical and bead blasting)
-Painting
-Restoring bakelite
-Rewiring every wire on the car
-Woodworking
-Using an ammeter
-Polishing paint
-Changing tires
-Changing head gaskets (and every other gasket)
-Rebuilding carburetors
-Rebuilding speedometers
-Modifying key switches
-Restoring gas gauges
-Restoring spark plugs
-Using a gauge to measure and adjust gaps (points, plugs, etc.)
-Using taps and dies to cut new thread and chase old threads
-Arranging and restoring bolts by color (cadmium, raven, etc.)
I've also spent many, many hours in the Judging Standards to figure out what my cars should look like and then, for my E28 RHD Model A, going through the Ford archives and pulling original factory drawings, engineering change orders, etc., and THEN bugging other collectors for photos of their cars and associated parts to confirm factory specifications.
It's been a fun journey so far. Shortly, I'm going to start taking apart my Phaeton and completely restore it. I'm certain I will be able to add more skills to the list.
Dave