I have 2 mates who are mechanics.
Ones a 4th year, the other is fully qualified.
Both find it hard to get the motivation to work on their own cars since they're working on customer cars all day. The pay is also beyond shit. One of them works at a large Toyota dealership and the other works at a Holden dealership, but will soon move onto a custom engine building workshop.
For the shit pay you get once you're qualified, and the amount of work you have to put in just to make a decent buck, it's put me off becoming one. I'd rather be a weekend mechanic and actually enjoy working on my car, rather than making a career out of it.
In theory it sounds fantastic, and the first few weeks might seem all roses and cup cakes... but after a few years, like my mates, they all want to get out of the industry and into something better paying.
And at the end of the day, you're either a mechanic for someone or you have your own workshop. There's no real... working your way up.