It's one of those amazing alchemical things, like how tomatoes are made out of water and sunshine with trace amounts of dirt. Babies are made out of milk. Rebecca was born a scrawny little useless thing, we fed her milk, and here, a year and a bit later, she's a sturdy capable toddler. We may have fed her other trace ingredients, like stories and hugs, but by volume it was mostly milk. Pretty amazing.