"Nature Study, The Elixir of Youth
...After all, what is the chief sign of growing old? Is it not the feeling that we know all there is to be known? It is not years which make people old; it is ruts, and a limitation of interests. When we no longer care about anything except our own interests, we are then old, it matters not whether our years be twenty or eighty. It is rejuvenation for the teacher, thus growing old, to stand ignorant as a child in the presence of one of the simplest of nature's miracles--the formation of a crystal, the evolution of the butterfly from the caterpillar, the exquisite adjustment of the silken lines in the spider's orb web. I know how to 'make magic' for the teacher who is growing old. Let her go out with her youngest pupil and reverently watch with him the miracle of the blossoming violet and say: 'Dear Nature, I know naught of the wonderous life of these, your smallest creatures. Teach me!' and she will suddenly find herself young." [page 4]