The very least you can do in your life is to figure out what you hope for. The most you can do is live inside that hope, running down its hallways, touching the wall on both sides.

Let me begin that way: with an invocation of your own best hopes, thrown like a handful of rice over this celebration. Congratulations, graduates. Congratulations, parents, on the best Mother's Day gift ever. Better than all those burnt-toast breakfasts: these, your children grown tall and competent, educated to within an inch of their lives.

What can I say to people who know almost everything? There was a time when I surely knew, because I'd just graduated from college myself, after writing down the sum of all human knowledge on exams and research papers. But that great pedagogical swilling-out must have depleted my reserves, because decades have passed and now I can't believe how much I don't know. Looking back, I can discern a kind of gaseous exchange in which I exuded cleverness and gradually absorbed better judgment. Wisdom is like frequent-flyer miles and scar tissue; if it does accumulate, that happens by accident while you're trying to do something else. And wisdom is what people will start wanting from you, after your last exam. I know it's true for writers - when people love a book, whatever they say about it, what they really mean is: it was wise. It helped explain their pickle. My favorites are the canny old codgers: Neruda, Garcia Marquez, Doris Lessing. Honestly, it is harrowing for me to try to teach 20-year-old students, who earnestly want to improve their writing. The best I can think to tell them is: Quit smoking, and observe posted speed limits. This will improve your odds of getting old enough to be wise.

If I stopped there, you might have heard my best offer. But I am charged with postponing your diploma for about 15 more minutes, so I'll proceed, with a caveat. The wisdom of each generation is necessarily new. This tends to dawn on us in revelatory moments, brought to us by our children. For example: My younger daughter is eleven. Every morning, she and I walk down the lane from our farm to the place where she meets the school bus. It's the best part of my day. We have great conversations. But a few weeks ago as we stood waiting in the dawn's early light, Lily was quietly looking me over, and finally said: