Never did time on the ground,but I was in the national guard before I joined the navy (lack of capitalization intended) and we did something in the early 90's where we'd man fighting positions an hour before dawn an hour after dusk, as they claim that those were the most common times to attack (And I guess some of the old timers told me that Korea/Vietnam backed that up, but with even the most backwards of insurgents having night vision, not sure that really is accurate anymore.) And to this day, I wake up at 0430 no matter what time zone I am in.
On a submarine, you have multiple fans running. And air blowing. If something changes, like fan cutting off, it is an indication of something that is wrong(SHit hitting the fan HAHAHAHAHAHAHA!!!). I can't sleep without a fan or an AC going, and if I go to sleep, if something like a loud noise wakes me up, due to having to fight several causalities(General Alarm. Buddy did that to me a few times after I got out, and after the third time, I decked him, and he decided it wasn't a good idea... ((Fire,Flooding, Hydraulic Rupture, Diesel engine exploding, etc etc etc)) the adrenaline is pumping and you have to do something or else you are laying in bed fidgeting. So I got for a walk, getting a water from the grocery store and walk back.
As far as sleep goes, even after ten years, I love to sleep. I can't get enough. I say I am catching up from the fast attack fleet. And as far as that goes, the submarine rack is abut two feet wide, six some odd feet long, and about 18 inches high, and to turn over, you learn to throw yourself in the air, and turn doing that. I still do that, and I still sleep in the same space that is equivalent to a submarine rack. I also sleep pretty much on my sides, whereas before joining the navy, I loved sleeping on my stomach. Now I can't.
Injured my knees while in, and I suffered because of that. Healed them via various alternative treatments, but to this day (Torn meniscus, which according to a navy doc, the pressure that is present when they heal themselves remains, as they can no longer regulate their own pressure, so you become very sensitive to barometric changes) when the weather changes, I know when rain is coming. Bad back from the shitty sub racks, and migraines that many believe are caused by the untested Anthrax vaccinations they forced on us (I got one dose on one boat, 6/7 treatments, Doc didn't document it in my medical record, so got to my new command and got it again.) And because I was an FT, I spent a lot of time dancing with the one eyed fat lady(spinning in circles looking through the periscope.) and because my right eye was my dominate eye, I spent most of the time looking out the scope with that eye. As such, my left eye is much more sensitive to brightness than my right eye. If close one over the other, I notice a difference. This is due to natural day light vs the interior of the sub which is all florescent lit.
To this day, I love sunshine and sunsets and sunrises beyond most other things. Fresh air and food, I have an appreciation that some do not understand. I still love what many term as the smell of the ocean, (Which is actually supposedly the smell of land) as when you have been underway for a spec op for 100+ days, and they first open the hatches, and you smell that, it means the ordeal is over.
Despite that being as bad as it sounds, I get along pretty well in life, and I have learned to adapt. The study of philosophy has helped me to find peace with most of it.
Oh, and the smell of amine. It makes me puke to this day.
The service always affects you. Not much you can do about it. Adapt, or don't. You can only control how you react to things.