One thing to realize is that job shops run the same parts over and over. Put the material in, push the go button. Sit on your butt and wait for the part to be done. move it o the next fixture, install more material, pull out the completed part from the fixture....just like an assembly line. I work for an extremely huge corporation, we are the largest exporter in America, and I work on machines, fixing them is way more desirable of a career. You have to know something about computers for the CNC, you have to know about the mechanics of machines, lube systems, wiring, belts, safety requirements, etc. Fixing can be a dirtier job but it pays $5 per hour more than what our machinists make. Some of the repetition for doing preventative maintenance gets old but the troubleshooting can be both frustrating and fun.
I also have an A&P license with inspection authorization and have worked on everything form a Super Cub to 747-400, working nights, out in the cold, and on weekends was the norm for that job, now I just do it for a hobby, taking care of a few airplanes for some extra cash and a change of pace on an occasional weekend. Liability is high if there is an accident or crash but its the nature of the job.
Pick your career wisely. I looked at going to machinist school 27 years ago, instead, I went in the Air Force for 5 years, then joined the Army for 8 more, working on F-15's then Huey's, Blackhawks, and lastly Apaches. Loved the Huey the most, got to fly with that job. After getting out, I worked on modifying nuclear missile silos, then did building maintenance for the Missile Defense program, finally ended up working on machines. My current company pays for education so I am finishing my Doctorate of Management in Homeland Security. This is a little about my career changes, I loved the mission and teamwork of the military, it gave me my start and paid for my Bachelors degree, masters was paid by my employer at the time. I do regret not taking a few risks and getting my Commercial Pilots license, now I just have a private. I am considering a career change in the next couple of years, its just what I do. I have a good retirement now and stable work but doing the same thing too long bores me and I like new challenges, others are happy doing the same thing for their entire career. It's up to you to decide. Good luck. Tim