My favourite book as a child was Velveteen Rabbit. I recently reread it and it still is.
It was written by Margery Williams Bianco. This quote stood out to me probably more than when I was little.
“Generally, by the time you are Real, most of your hair has been loved off, and your eyes drop out and you get loose in the joints and very shabby. But these things don’t matter at all, because once you are Real you can’t be ugly, except to people who don’t understand.”