The parenting quotes that strike a chord with me come from a variety of places. Here's one from John Peel's autobiography (well the bit written by Sheila Ravenscroft) - it's from memory so not completely accurate i'm afraid.
'One of John's favourite memories is seeing Danda [their eldest daughter] in town one day when she was 15, heading off with about twenty of her friends to the field where Stowmarket's teenagers have their fun, for an afternoon of getting hammered on cheap cider and Lambrusco. He was filled with pride and contentment. She was enjoying her life, he realised.'
and from Katherine Whitehorn's How to Survive Children -
'You know which children you like to have around, which ones you can really stand - your own. You must be doing something right.'