My daughter has been such a gift for me and my wife -- a really loud and sleepless and scary gift. I don't think I'm capable of doing anything better for the world than helping bring her into it; the thought is both humbling and depressing.
These days I actively reflect on just how much assumed knowledge and cumulative experiences I carry around with me. Every day holds something new for her, and everyday my wife and I are challenged with helping her make sense of it all. (I think there are a lot of similarities between parenting and interaction design, but I've yet to have a stakeholder giggle when I blow raspberries on their belly.)
I've been delighted and fortunate to relearn a lot through my daughter's experiences; the triumph of standing up for the first time, the terror in falling and bumping your head, the disappointment in learning that mommy doesn't really disappear during peak-a-boo, and the pure fucking joy in those first bites of frozen yogurt.