Cadet at 19, RH seat at 21, fly for 6 years, pay off the bond, Jet* ditches you because there's other cheap-as cadets to fill your seat, you decide there's better money in building/plumbing/electrician, so at 27 years old you have had your first career - as an airline pilot - then you move on.
I can see this becoming the norm. It is regarded that the gen-y teens today will have 4 or 5 careers (not just jobs) before they retire. Hell I've had 3, and my kids are gen-y teens!