It’s just not as hard as it may seem.
I taught myself at around 12-13yrs old – my parents were skint, so I saved up and bought myself a Raleigh Bomber ‘Super’, then a Raleigh Pulsar road bike.
I tinkered and I read books about them – I looked on in awe as my old man (step dad) bought a Muddy Fox Courier and his mate had some ‘fancy’ Dawes ‘proper’ mountain bike.
At that age I’d probably have avoided most things with bearings and spokes, but I was learning – some pals couldn’t even sort a flat tyre.
I still wouldn’t know where to start building a wheel and servicing forks remains the domain of the experts – I suppose the rest of it is quite simple to me, but to that extent shouldn’t really be outside the comfort zone of anyone given a bit of practice and research.