Yeah certain Zidane didnt joined Juve until 24, and he was projected to be flop after poor showings in Euro 96
And lets not forget in 1996-1997 season, when Juve pratically changed half of the team, everyone was tipping Milan to win the title by streets, we were the one who won the title easily with "not so hot prospects" which include 22 year old Vieri, and mid 20 Paolo Montero (and he was good back then

).
Oh, Kaka is "already" 23 that is why we may have missed him.

.
Sorry, but you cannot define who has potential or not by arbitary criteria of being teenager. Some develop early and some later.
While I do agree that Enzo isn't quite at Emerson level yet (after all the guy is probably top 5 midfielder in the world), and he may never reach that level, but to say he doesnt have a potential is just pure ignorance and prejudice on age.
I say it again, Enzo is our future.