I once had a TG9 Cpl working for me who was ex French Foreign Legion, joined the RAF on the promise of Tac ATC etc and then spent most of the next 12 years doing his nut in various towers, desperately volunteering for anything vaguely war like without much joy.........
We had a CPL armourer. In the same boat, joined as an armourer and promised he could remuster once in to a musician, had a degree in music and was a qualified teacher, was gutted and held a chip about it throughout his career.
Strange how the FOO position has the same traning period as the assistant... 12 weeks