Conversely however, I think it's also a mistake to think "Oh haven't found a wife, well I guess I'll become a Priest since I'm celibate either way." One should actually feel a calling to the Priesthood, it shouldn't just be a backup plan in case you don't get hitched.
This is also a non-problem. It's not as though just any man (especially a man who still hasn't "found himself" or established himself by age 40) could make it all the way through 6 years at the seminary! There is a certain rigor to the daily routine of spiritual duties, silence, work, and STUDIES. In human terms, there is a minimum IQ necessary to become a priest, and I'm wagering that IQ is something above "the average" IQ.
Even in today's depressed intellectual environment, seminarians need to learn Latin. They also need to gain a certain baseline mastery of several subjects, including Moral Theology, Ascetical & Mystical Theology, Philosophy, Canon Law, Liturgy, Scripture, Church History, etc. In the good old days, they learned Latin, Greek, and sometimes Hebrew. There were more courses as well, like Scriptural Exegesis, Homiletics, etc.
They also need to be able to handle stress (Sunday is not a "day of rest" for Trad priests!), deal with many kinds of people, be organized, etc.