I can tell you about being a 19K (armored crewman) in the Army.
Everything centers around the tank. "Horse, Saddle, then Rider". That means you take care of your tank and equipment before you take care of yourself.
Crew integrity is everything. Loader, driver, gunner, and tank commander are a team. Any differences you have with another crewmember must be forgotten when you mount up.
your track is your home, your suit of armor, a physical extension of you and your crew. Respect it as such.
Your track is designed to kill. It's a job that it does very well. It is not partial and will kill you or someone in your crew if you get sloppy.
Field training excercises means:
Combat or gunnery excercises at 04:00 because that's allegedly when your enemy is at his weakest
Breakfast:" Hot A's" Scrambled eggs that have been turned green by the aluminum in the mermite cans and undercooked bacon or overcooked black sausage patties. Sometimes it's SOS. "Hot A" is a minomer as they are never hot. "A" might apply though as they typically taste like ass.
Track maintenance and more excercises
Lunch: MRE. Circa 1988. dehydrofrozen pork pattie or chicken a-la scratch.
Track maintenance and more excercises
Dinner: Tray rations. Sometimes these are actually still hot but moving around 60+ tons of death machines stirs up a lot of dust so you inevitibly get some grit. That's also when the flies find you.
Track maintenance and more excercises
Hour or two of sleep then radio watch or track maintenance and more excercises....
In spite of all this, it still beats being in garrison where the REMFs will have you do all their jobs for them unless you can escape to the motor pool to work on your track.
You do get less micromanagement than you would in the Navy or Air Force. I've trained alongside the Marines and they live pretty much like we do except they have to take s**t from much less qualified Navy personnel regularly. And Marines must practice D&C a lot because those MF'ers can march well.