Is there any genre more riddled with cliches than the college commencement speech? All the tortured metaphors, saccharine anecdotes, and other heavy-handed attempts to impart wisdom to soon-to-be-grads sweltering in the hot sun in their polyester caps and gowns -- well,  it's enough to make George Orwell blush.

But Harvard historian Nancy Koehn says we shouldn't be so quick to dismiss the genre. She joined Boston Public Radio today to convince us that there's still a way to make meaningful the pomp, circumstance, and (occasionally) prattle of Graduation Day.

Koehn's gold standard is David Foster Wallace's offering at the 2005 graduation of Kenyon College. He kicks off the speech with maybe one of the most cliched of all cliches: a didactic parable. But don't close your browser just yet. Take a look:

When Wallace launches into his story about three fish, we think we know exactly where it will lead. We wait for the older fish to teach a valuable lesson to his young and confused counterparts. Considering the setting, we assume that valuable lesson will probably be an assurance that, after four long years, the young graduates in the audience have learned good, rigorous, and proper ways of learning and thinking, as evidenced by the nicely embossed pieces of paper in their hands.

This is where we're wrong. Wallace's parable isn't so much a reassurance as it is a challenge: a challenge to, as he puts it, get free of our "natural, hard-wired default setting" towards self-centeredness and continually question the things we automatically assume to be certain.  "Because a huge percentage of the stuff that I tend to be automatically certain of," he admits,  "is, it turns out, totally wrong and deluded."

Hear Koehn's full take on "This is Water" - along with her picks for other commencement speeches that have stood out from the rest - below.