Many Years?
It was never stated that it would need to be many years before Jack could enter the portal. The portal does show Jack when he is much older, but there isn't significant evidence that that's the age he needs to enter the portal at.
I believe the implication is that he won't have enough experience or skill to finally defeat the Guardian until he has reached that age.LunarDelta (talk) 03:08, May 1, 2014 (UTC)