A first for us -- our son is now a missionary. Quinn entered the MTC on Wednesday, headed for the Oregon Eugene mission. He is totally ready for this -- as ready as anyone can be. He graduated from early-morning seminary. We studied the entire Preach My Gospel manual in our morning devotionals his last year of high school. He took Missionary Prep at BYU (from Brad Wilcox). He has had part-time jobs outside of the home since he was 14 -- he knows how to work. He learned how to live alone during his freshman year of college. He has a strong testimony and a desire to serve God.
The thing he struggles with, and a big reason he would have benefited from going on a mission before college (if the 18 option would have been available then), is time management. As a junior companion he's GOING to learn to plan out his day in detail and be accountable for how he uses his time. By the time he's a senior companion he should have that one (mostly) conquered. And that will certainly be a blessing for his sophomore year at BYU. I say this because we were up until 1 a.m. the night before he left working on some things he had to do before entering the MTC -- things he'd known about since his call came six weeks before. He "didn't think they'd take so long." Classic.
I can't talk though -- as Paul knows, I always think things will take less time than they do too. And I've survived to become a fairly successful adult -- he will too. But the mission will help.