How to mop floors and operate a floor buffer in the Air Force.
Not meaning that as derogatory or demeaning by any account. Everything I learned in both the Air Force and the Army had practical application. Maybe I didn't use it right away or for even years in some cases. But sometime, somewhere, everything I learned in the military came to hand in a useful manner.
Talking the odd things, here. Not combat skills-which don't or at least should not be a skill transferable to the work-a-day, live-a-day world.