The ups and downs of youth are the best memories in this life, because they cannot be recreated in this life. We all don't have a God's perspective and can't see so many alternatives, so we only know how precious it is after we lose it.
Purpose: There is no absolute right, wrong or perfection in youth. Every experience is a unique mark of life. Learning to reconcile with past regrets is the best tribute to youth - only by accepting all scenery can you rush forward lightly.