First experience was helping my Dad work on his 1946 Chevy. I was about 6. Mostly it was my job to hold the flashlight while he worked on it. I remember getting yelled at when the light drifted from the spot it was supposed to be shining on.
On my own was when I was about 11. I bought a go-cart from a guy for $5. I didn’t want the go-cart. I wanted the 3hp Briggs that was on it. I completely disassembled the Briggs and got it running. I learned a lot about magnetos, carburetors, valves and valve timing, etc.
I saved my money and bought a mini-bike kit, installed the Briggs and off I went. I still have the scars to prove it.
Later (early 70’s) I graduated to British cars. Need I say more?
When I was about 11 or 12 (1962), my Dad gave me the “Visible V8” model. I learned all about four stroke Otto cycle engines with that model. Shortly after building that, I completely disassembled our Briggs & Stratton 3-1/2 hp lawn mower engine. There wasn’t a screw or bolt fastener left undone. I cleaned everything up real good and used Gumout solvent to get varnish off the carb parts. Got it reassembled and it started on the first pull.
It was a lot harder in those days because manuals were scarce, there was no YouTube to watch how-to videos, and you didn’t take pictures on your phone as you disassembled things. You had to be well organized to store all the parts and have a good memory.
I went from there to oil changes, changing shocks, rebuilding Holley four barrel carbs, changing starters, replacing failed camshafts, and pulling heads for valve jobs. Then I started making some money and paid others to do all that work for me.
But those were fun days.
I asked my Dad once why he didn’t join me on that work. He said “I pay others to do that stuff”. He used his rare time off to play golf.
My first, last, and forever British car was a ‘67 (?) Sunbeam Imp (a Shelby creation). Fast and fun with a horrible oversteer.