Honestly, I wouldn't mind being more knowledgeable about cars. I'm just afraid to touch anything, because I figure I'll break it and incur a massive bill to replace whatever part I broke. PC operating systems carry no such risk; you can give up on whatever you're trying and reinstall your old OS at any time without paying anyone anything.
Even PC hardware isn't that risky to tinker with. It's an order of magnitude cheaper than a car; lots of people have old, obsolete, but perfectly functional PCs lying around that they'd like taken off their hands; most components are within easy reach; and the component that isn't within easy reach (the power supply unit) is pretty tough to break.