I've taken courses through manufacturers and done a lot of reading and tinkering with stuff over the years. It used to be that most kids I knew had taken apart the gear assemblies on their bikes, redid the brake cables or modified them when they lengthened the front ends to make bicycle choppers, changed the oil in the family car when the dad was too busy, lazy, or drunk to do it by the age of 12 or 13. We delighted in going to the junk yard or the dump and finding stuff to tear down and put back together.
I was under the hood of my dad's 74 chevy 4wd truck replacing the fuel pump at 14. Hey it was raining and I could just about fit in the engine compartment and close the hood part way. When we got our minibikes and motorcycles we never took them in for service. We did em ourselves. Now I work on high pressure (45k-97k) waterjet systems.
Gear repair and maintenance is not hard, not rocket science, and is as was already stated mostly common sense. My GF learned to lighten the trigger spring in her handguns from a book and help from members of her shooting message board. And you tube videos. Great stuff there. There is in fact one on rebuilding the inflator found on many BC's. It's in german but the video is good and it is a simple fix. regs are more complicated but the right tools, patience, and good guidance can get most mechanically minded people through it. If you think though that changing the oil on your car requires going to the dealer you might want to rethink doing your own regs.
Note this is not the same as not changing the oil because you don't want to hassle with it. That is ok.
