All of what Gonzo says!
Equally, having passed the selection and college courses doesn't guarantee achieving validation -
I believe the general rule of having 12 months in between applying is so that the applicant will maybe have had more experiences which may stand them in good stead for next time. (I realise that you are 28 - I don't mean to patronise you - some folk who apply are only 18)
And it isn't cheeky to ask for feed back - how else would you know what to improve?!
Good luck for next time
louby