I was in the Army for seven years, and Army Reserve for one year. I was a mechanic in aviation. I would have stayed in longer but I started having trouble working after a head injury.
I loved the military structure, constant training in new things, the technical and hands on aspects, physical training.
I didn't like the office politics and social manipulating in some workplaces. Also sensory issues got in my way at times, mainly strong smells and strong sounds (large amounts of cigarette smoke, some paints and solvents I worked with, chronic loud music in the barracks).
Back then I had no clue I was autistic, but I wondered why I was so different, mainly because of my sensory issues, but also because I could tell that my brain thinks a heck of a lot differently from most people I had ever met.