“By the time it came to the edge of the Forest the stream had grown up, so that it was almost a river, and, being grown-up, it did not run and jump and sparkle along as it used to do when it was younger, but moved more slowly. For it knew now where it was going, and it said to itself, "There is no hurry. We shall get there some day."”

The Notebooks of Leonardo da Vinci (1883), XXI Letters. Personal Records. Dated Notes.

Source: Culture and Value (1980), p. 17e

Source: Autobiography of Mark Twain, Volume 1 (2010), p. 210

Regarding stopgap measures for the federal budget, White House press conference (11 July 2011) http://www.whitehouse.gov/the-press-office/2011/07/11/press-conference-president
2011, Remarks on the economy (July 2011)

"On Three Ways of Writing for Children" (1952) — in Of Other Worlds: Essays and Stories (1967), p. 25
Context: Critics who treat adult as a term of approval, instead of as a merely descriptive term, cannot be adult themselves. To be concerned about being grown up, to admire the grown up because it is grown up, to blush at the suspicion of being childish; these things are the marks of childhood and adolescence. And in childhood and adolescence they are, in moderation, healthy symptoms. Young things ought to want to grow. But to carry on into middle life or even into early manhood this concern about being adult is a mark of really arrested development. When I was ten, I read fairy tales in secret and would have been ashamed if I had been found doing so. Now that I am fifty I read them openly. When I became a man I put away childish things, including the fear of childishness and the desire to be very grown up.

Walking on Water (1980)

Acceptance Speech for the Margaret Edwards Award (1998)
Context: I've always believed that there is no subject that is taboo for the writer. It is how it is written that makes a book acceptable, as a work of art, or unacceptable and pornographic. There are many books circulating today, for the teen-ager as well as the grown up, which would not have been printed in the fifties. It is still amazing to me that A Wrinkle In Time was considered too difficult for children. My children were seven, ten, and twelve while I was writing it, and they understood it. The problem is not that it's too difficult for children, but that it's too difficult for grown ups. Much of the world view of Einstein's thinking wasn't being taught when the grown ups were in school, but the children were comfortably familiar with it.

Source: Madeline Carroll: I Almost Quit Acting ForGood Before Being Cast In ‘I Can OnlyImagine’ https://hollywoodlife.com/2018/03/16/i-can-only-imagine-movie-madeline-carroll-interview/ (March 16, 2018)

Source: Lady of Mazes (2005), Chapter 24 (p. 265).