I took small engine repair as a sophomore, 1982, and my junior/senior year I was in vocational auto repair. I hired into a diesel shop as a junior and was mostly a "wheel" mechanic. I was "apprenticing" under an old guy and was pulling sleeves and sech with his supervising re-assembly.
Never had a mom or dad but had worked on local farms and had my 1st car, '67 Galaxy, before I had my license. Knew a couple guys who'd let me hang out in their shops and worked on my own stuff.
My '74 Chevelle, Laguna S-3 was my "1st build" and that factory 454 didn't stay stock. Lost my license rite after high school, hot-rodding, still working in the diesel shop and kept getting caught driving to work w/o a drivers' license.
Joined the Army, did my 3 years and "wrenching" had lost it's magic by the time I got out.
Went to school after the Army and went to work as a "Radiographer",,ie. x-ray technologist, not a "technician"!!
Still work on my own junk and will fettle with my brothers/nephews auto's too. Just to beat the mechanics' shops.
I've always kept new/newer chainsaws and mowers and sech so I don't get to work on 'em much.
I've reached the point in life where I'd hire any serious engine repair on my autos if they needed it. Still do water pumps, wheel hubs, brakes, transfer gearcase swaps,and the like,when I need to.
I've built a couple old Shovelhead engines and been thru a couple "evo" engines back when I was riding 'cycles. Never split the gearcase on any of 'em.