I have been told by almost all priests I have talked to that they encourage young people to enter sooner rather than later, and that they wish they had entered sooner rather than later.
And for religious life, it is apparently even more urgent, many Superiors telling me outright not to go to college if I think I have a vocation, that the education can be handled later, but that “if you go to University, it will most probably destroy your vocation, and you might even lose your soul…” I heard that sentiment and similar statements many times.
All the traditional literature, all the stuff written pre-1970 promotes earlier rather than later.
But I’m not saying that in individual cases an older person can’t have a vocation. Better late than never. After the fact, you can’t go back in time and enter earlier…so we should let them in if they’re sincere.
But that’s only after they’ve already waited and are already older.
But for a young person today, asking whether they should go or wait, who still has the luxury of that choice, I’d say the answer is a resounding GO!
For those whose only option is entering later (since they* already* didn’t enter sooner), of course we should definitely let them in. But for people who still have both options, to wait or not, we should definitely encourage them NOT to wait.