I liked the mechanical side of things, and pride in helping people make their vehicle run better. I also took pride in helping people save money, I know that some people don't know anything about vehicles, but that shouldn't be a good reason to gouge them on the price, I don't appreciate when businesses try to do that to me, so why would I do that to other people when the tables are turned? Troubleshooting problems, after a while you get used to the in's and out's of the job so it gets like riding a bike or something.
However it was also dirty and dangerous, you are almost certain to be hurt every day. I don't think putting hot used motor oil against your skin is good for your health. Uneven work pace, trying to predict when customers will come is random. Basically no chance for promotion. It's also low paying.
Mechanical work, sense of pride in helping people, familiarity.
No lunch break, dealing with old motor oil, dangerous, dirty.