We learned how to fix bikes by breaking bikes. Yes, seriously, BMX, SERacing, Road Bikes, MTB, gravel, kids, and everything in between!
Zack was in 5th grade and wanted a nice new bike. We went to the old Performance Bike shop in San Mateo, CA and bought a nice, simple, 24", hybrid. Every other day Zack would either blow out a tube, break a seat post, damage brakes, untrue a tire, see you get it. He loved riding.
The guys at Performance knew Zack by name and treated him as a bike enthusiast not a 9 year old kid. They got tired of fixing his bikes so this guy Nathan one day said, Zack, get back here and I will show you how to fix this stuff. The rest is history. Basically by 14 he became a top level mechanic. Now he teaches others while turning his passion into a business.