By Meghan Daum: Commencement addresses are a bit like wedding toasts.

Commencement addresses are a bit like wedding toasts. A handful are memorable; the rest tend to trigger such musings as, "Why did I wear such uncomfortable shoes?" "Will anyone notice if I send a text?" and "How drunk am I likely to be by the end of the evening?"

But unlike nuptial tributes, which (unless you're in Japan, where they often hire pros) are delivered by unpaid amateurs, graduation speeches are less about the message than the messenger. Every year, a few colleges and universities attract attention because they've managed to book high-profile speakers, and, every year, the media dole out snippets of these speakers' sage remarks.

In the last week, the following nuggets of wisdom have been dispensed:

"You really haven't completed the circle of success unless you can help somebody else move forward." (Oprah Winfrey, Duke University).

"There is no way to stop change; change will come. Go out and give us a future worthy of the world we all wish to create together." (Hillary Clinton, New York University).

"This really is your moment. History is yours to bend." (Joe Biden, Wake Forest University).

I saw you dozing off just now. I saw that!

Not all of last week's speeches trafficked so heavily in motivational sanctimony. President Barack Obama's Notre Dame address on Sunday doubled as a diplomacy effort in the fomenting battles over abortion rights. The president also spoke at Arizona State University on May 12, though his comments there — "I know starting your careers in troubled times is a challenge. But it is also a privilege" — were more pep talk than polemic.

Of course, the real "get" of the graduation season was first lady Michelle Obama's appearance at the University of California, Merced, a new campus in an economically challenged region of Northern California where many students are the first in their families to attend college. "Remember that you are blessed," she told the class of 2009, the first at Merced to enter as freshmen. "Remember that in exchange for those blessings, you must give something back. ... As advocate and activist Marian Wright Edelman says, 'Service is the rent we pay for living ... it is the true measure, the only measure of success.' "

Calls to service have a long, rich tradition in these speeches. I couldn't help noticing that Laura Bush, at Southern Methodist University, hit many of the same notes as the current first lady's speech. "You won't waste your talent and education if you use them in service to others," she told the graduates. (She also delivered a rather hilarious aside about not remembering that her own father-in-law was the speaker when she received her graduate degree from the University of Texas.)

It's hard to argue with exhortations to serve, especially in an economy in which a diploma isn't necessarily a passport to gainful employment. And let's keep in mind that these speeches are in many ways less for grads than for their parents, some of whom (you know who you are) perhaps want a little oratorical gravitas to offset the knowledge that they mortgaged their house so their kid could take classes like "Star Trek: A Semiotic Inquiry."

Of course, it's possible for a commencement address to transcend conventions and cliche and say something truly compelling. The late writer David Foster Wallace's 2005 commencement speech at Kenyon College in Gambier, Ohio, which talked about, among other things, how to authentically care about other people, gained something of a cult following after it was widely circulated on the Internet (it's now available as a book). Steve Jobs' address at Stanford University that year, in which he talked about death, is also considered one of the best in recent memory.

But when you're sitting in the hot sun in your gown and mortarboard, fidgety and freaked out, do you really want to be lectured about the big stuff? Isn't that like trying to maintain a beatific smile at your wedding reception while some wearying relative gives a toast that amounts to "marriage is hard work"? You know he's right; you just don't want to think about it at that particular moment. In fact, as is the case in many major life moments, you can't really manage to think beyond the blisters your shoes are causing.

That may seem crushingly anticlimactic, but it also gets to the heart of one of life's greatest, saddest truths: that our most "memorable" occasions may elicit the fewest memories. It's probably not something most commencement speakers would say, but it's one of the first lessons of growing up. Another word for that is "graduating."

Daum is an essayist and novelist in Los Angeles. E-mail Daum at mdaum@latimescolumnists.com.