Construction work isn't for everyone. If you're that army guy who puts in the minimum effort, expects things handed to you, can't comprehend working past 4:30, needs thorough and complete direction to accomplish a task and requires constant 'admin time' to go about your daily life then you better find a way to stay in the military forever.
Construction work is a daily challenge. You are building things, repairing things, conceptualizing things often without any plan, minimal plan or an unworkable plan yet there is no option other than success. There are deadlines and they will hit you in the pocketbook if you fail.
I certainly had my challenges serving a couple decades in the army, but never at the level of running a contracting business. I find it incredible that someone might think of this sort of work as mindless. That attitude could only come from an over inflated belief in their own worth to society or a blissful ignorance of what sort of process may have been involved in constructing, heating, plumbing, electrifying, networking and operating the buildings they spend so much time in. A big part of the reason we have a shortage of skilled trades is that the level of skill required has gone through the roof over the past couple dozen years.
Do not get yourself in a knot over 'experience' and 'training'. When I hire apprentices, i'm looking for commitment, intelligence and reliability. One the best I ever hired had been working as a ski lift operator. Another was a PTSD case from the PPCLI. I used to assume that being military meant that a candidate was bringing reliability and understood the meaning of timings. Nothing could be further from the truth. What I have learned is that the army often leaves its soldiers in a similar 'institutionalized' state as the unfortunate older black guy from
The Shawshank Redemption. Years of being told exactly what to do and how to do it combined with a self-contained system of medical, dental, material and administrative support can leave a person unprepared to function in the real world.
If you are military and looking for civilian work, you need to emphasis that you are adaptable, intelligent, free-thinking, committed and can deal with your own problems on your own time. Expect to be challenged, expect to work long hours and expect to be well compensated for it.
I find it very gratifying when I walk into a structure I helped build and know that it will be there serving a real purpose for years to come. If you're the sort of person that takes a great deal of pride in what you do and enjoys the sense of accomplishment that comes with a job well done, then the trades are for you.