People throwing money at cars to try to fix issues without actually using any diagnostics or common sense... or just doing that then selling a car cause of small issues they can't figure out and won't listen or ask for advice on.
I think that's why you have to have an emotional connection to your car at some level. If you're looking for a reason to quit, it's too easy to find one.
I'm shocked at how many people whose cars have issues say that they don't have a service manual...