Funny tale on how my buddy made Sgt. He was stationed in Japan, 1960's. Job was to guard war plans, deliver them to a General upon request. One morn he delivered a plan.
General: Why aren't you e-5? You have the time.
Buddy: Sir, the Captain says no promotions to those who don't show up for morning PT.
General: But you're working for me then. I'll speak to the captain.
My buddy was e-5 that afternoon.