Well, there are no guarantees of course... but if you failed on lack of life experience then I wouldn't imagine it would be hard to convince them to give you another go in 5 years time.
If that was your only reason for failing I'd imagine you'd be one of the ones they'd ask back after 6 or 12 months anyway.
Like I said, no guarantees but if you don't think Uni is for you I wouldn't go through it for the sake of another box ticked. Ultimately if you succeed at CTC (remember it's not just selection you have to pass... you have to actually make it through the course too
) I'd imagine the few thousand hours you rack up in the years you would have spent at uni would be of equal or indeed more value than a degree.
All in my humble opinion of course, take it as you will.