I have been thinking abit and i think the career system is strange. if im in one career and i have finished it (spent 10 xp) why cannot i , instead of having to change to some occupation i dont want to be, rather do the same career again, and specialize ?

is this possible ?=

By the RAW, no.

But you could house rule it, or even if your career card was something else/similar you could still play as though you were your original career.