That's pretty much what I did, though I didn't bother with the commission (bigger mess bills)
. In Transport & Movements (RCT), recommended, got sergeant at 22. Finished off my Os and As (yes, that far back) on the flying course. The beauty of the military is that they are able to see potential and work on it without necessarily requiring formal qualifications.
I do get your point melmoth, but there have been many from privileged backgrounds who didn't make it either.
phil