When I was 45 I got the urge to repair something with the lawnmower. So I took off the top, and peering down into the engine, I saw many parts, and I had no idea what they did or how to remove them such that I could get at the problem. In fact, I don't think I ever identified a problem; I just had a a symptom, probably something along the lines of "she don't corner like she used to," which of course would have pertained to the wheels, which didn't matter to me, given that I was going to disassemble the engine.
But I'm no dope. After I gasped I put the top back on the mower and took it to a mechanic down the road.
Similarly, I decided to change my own oil, and bought a pair of ramps, and even though the packaging said quite clearly, "Don't get under the car just using these," I did it anyway, indignant that having paid for what looked like it should work, wouldn't, and thus I would seek justice by defying that advice.
Quite irrational, but I was newly divorced and in the midst of employment woes, and at least half crazy. I was able to empty the oil and replace it with new but neglected to put the nut on the oil pan, and thus, driving, blew the engine within a half mile.
So you see like cigrmaster, best stick to a hammer and wrench and pay the mechanical adepts.