Mate,
airlines in Aus (the ones that employ these days anyway) no longer expect you to have 3 shuttle landings by 21. There is a vast range of experience among the entrants to the airlines, all of whom start at the bottom of the same list nowadays.
As for GA, being the non-Gen Y is likely to be a positive, if you've brought maturity commensurate to your age.
Don't be put off.