In-joke for the difference in culture between the services!
More seriously, the different services tend to have some differences because of the different ways they deploy - both in training/routine duties (away in a ship or submarine for months as normal pattern; usually at one location but sometimes bugger off for a long exercise; or perhaps be pampered with fluffy towels....)
But the biggest difference isn't between the services. It's between military and civilian.
The blue light services (and including trauma care medics) are arguably the nearest, and do have an element of putting themselves in harm's way and going that extra mile for others. But even though they can work long hours and need to stay beyond their hours, and sometimes have leave cancelled; they are generally in one place and not away for weeks at a time, and never mobilise to project force elsewhere. And if they do go to assist with disaster relief overseas, it's a volunteer, rather than being sent on 48 hours notice.
Edited to add:
The Navy sail the world, with thousand yard stares, and at at-oneness with the sea and the stars above it, which seafarers used, in days of yore, to navigate (the Navy is the Senior Service)
The Army are strange insanitary beasts, who can fight and sleep anywhere, including out in the field under stars (ka pongos, because where the army goes, the pong goes too)
The RAF stay in 4 star hotels and expect to be home in time for tea and medals. (Either that, or they're a bunch of garage mechanics).