What does growing up mean?

Errol sometime ago referred me to anime-style teenager Peanuts characters and these are an example.(see others here)

I have been a fan for many years collecting books and reading and even writing papers for courses in my academic studies about Peanuts. Here I ask How much have they changed in their teens?

Lucy the superbly self-confident and at the centre of her universe remains so. Linus always in the shadow of his big sister but maintains a mystical mysterious edge to him. Rerun the younger brother got lost in the mists of time. Charlie Brown, older brother to Sally remains the misfit and not so much at home in this world character, continues to wish the world were a better place and lives in the tensions of hope and reality. Hey am I describing facets of myself?

We ask God to give you complete knowledge of his will and to give you spiritual wisdom and understanding. 10 Then the way you live will always honor and please the Lord, and your lives will produce every kind of good fruit. All the while, you will grow as you learn to know God better and better. Col 1:9-10