Letting go means trusting God to continue to work in the life of the adult child that you have raised with his help. We are still growing, and our parents aren't micromanaging our lives. Now it's our turn to stand back and watch the process in our grown children. But that is especially hard to do if our own identity is too closely wrapped up in our kids. Then we have more at stake than their well-being, and we have burdened our kids with more than they were ever meant to carry.
Parents sometimes witness lapses in wisdom in their older children.
I'm 47, and I suspect that my mother sometimes sees lapses of wisdom in me. But she usually says nothing or very little. Maybe part of the wisdom that's supposed to come with age is in the humility that accompanies finding out how little you really have figured out. We want our children to glorify God and enjoy him forever. We want them to be men and women of godly character.