From childhood to adulthood

I don't know that there is any painless transition from childhood to adulthood. The change usually comes with its own cost. There are things from childhood that seem near inevitably lost. There are things from adulthood that are gained.
I would think true skill in living would be to know what to carry with us from childhood into adulthood and what to shed, like old skin.
Some things that worked in childhood do not work in adulthood. Childhood tends to be free and winsome. Adulthood can be over arching and all encompassing.
The biggest difference between the two worlds at least on the surface would be that childhood carries little to no weight of responsibility. Adulthood often trades this freedom for responsibilities necessary to survival.
Childhood is characterized by being parented. All needs are met by another. Provision is made by someone else's labor. Adulthood is the transition between being the one provided for to being the one providing. Maturity then could be said that we go from the position of self centeredness to other centeredness.
When someone fails to make this transition, he or she inevitably ends up relying on friends, neighbors, governments to replace the role of the parent in their lives. This most always put a strain on relationships.
Equally though, making the transition also carries with it a sort of death which I believe can be, should be avoided as well. Some make the transition so harshly that they lose the exuberance toward life that marked their younger years. Everything is business. Everything is about making money, being responsible etc. There is an emotionally flat approach to life. There is no room for frivolity.
I would think this state is a contributor to substance abuse. The human being is made with an instinct to play. When this is denied, some form of coping must be put in place.

My quest then is this: How do we "put behind us childish things" as Paul stated he did, and at the same time become like little children that we might enter the kingdom, as Jesus exhorted.

There is a place where we can develop the responsibilities adulthood requires without losing the awe stricken wonder at life that childhood is. I believe that the practical realm is meant to serve us and not the other way around. It is a difficult challenge and the process itself will make you a better person, but you can't lay down and die. It will eat you up if you let it. Nor can you ignore the fight and become a slouch. The only way through it is to train and tame the beast of the practical world to work and serve the higher calling as it is meant to. How we do this looks different for each person. For me it looked like going from never having signed my name on any official document, never writing a check or having a checking account, never owning anything I paid for myself to having a wife, owning a home, four cars and a business all in one year. Seven years later I am still learning how to keep the creative fires burning brightly, all the while growing and maintaining the necessary practical details that create a stable environment.