Haha, he thinks he's done with school. Haha.
For the rest of your life, you'll see people "get more" by going back to school, even if it's just night classes or a credit here and there. The USAF has totally bought into this to the point where the USAF has it's own community college offering an associates degree program, and you simply can't promote past a certain rank (both enlisted and officer) without further education.
The most effective Chief Master Sergeant I knew had a PhD, a handful of Masters degrees, and he taught Masters courses to a bunch of Lts and Capts. (through Embry Riddle).
If you quit learning, you get passed up. And then you find yourself sitting back watching everyone else reap the rewards waaay above/ahead of you. It's rarely "too late" to go back to school, but the punishment for not continuing your education is stagnation and, to put it kindly, putting yourself on the losing team in any contest.