When I was an undergraduate in England, one of my professors suddenly stopped halfway through his lecture. “Research shows that people your age can only concentrate for 25-minute bursts, so there is no point me carrying on,” he said. “Let’s take a break. But, rather than waste that time, let’s learn something random.”

He then described how to survive when approached by a bear. “If a grizzly bear attacks, play dead! However, if a black bear attacks, fight back!” He added an important qualification: “Only if you are sure that the black bear is a mother protecting her cubs … play dead!” The class erupted with laughter.

I do not remember anything else from that course. I can’t even remember its subject. Fluid dynamics? Optimization? But I do remember the bears.

I tell this story not to deliver an inspiring message about fighting back, nor to advise you, somewhat less inspiringly, to play dead. I imagine that you will be quite capable of distinguishing between the black bear and grizzly bear situations that come your way in life. No, I tell this story in praise of the unexpected, the informal, and the random knowledge one encounters in an undergraduate experience.

Twenty-five years later, faced with daunting 90-minute afternoon sessions teaching a class in the Science Center, I introduced my own lecture breaks. I delve into Harvard’s rich sporting past and the history of its cricket team. I speak of my experiences of 9/11 and how they found echoes in the days following the marathon bombings. I talk about great Cambridge mathematicians (“wranglers”), like Stokes and Maxwell, whose work created the applied math canon. I share Cadbury’s Dairy Milk and explore Salman Rushdie’s early career, writing commercials for chocolate bars. I reveal who really invented Bayes Theorem. I listen to David Willcocks conducting “Zadok the Priest.” And I uncover the connection between John Milton, Charles Darwin and Borat (all members of Christ College at Cambridge). I talk about random facts, memories and experiences.

As you process through the Yard today, amongst the applause, the speeches, the choirs, and the pounding of the Middlesex Sheriff’s staff, you will hear another sound: the clank of knowledge falling from you. P-sets are complete, finals taken, essays written—and we faculty all appreciate that you will start, happily, to shed chunks of what you learned in formal instruction at Harvard in the lecture hall, laboratory, and library.

But we are equally sure that you will retain into the future much from your informal Harvard experience: late night conversations with friends; unexpected interactions with professors; moments of self-discovery; surprising insights; random knowledge.

You leave Harvard supremely proficient in a variety of disciplines. Many congratulations on your achievements and your scholarship; it has been an unqualified pleasure to play even a small part in your Harvard education.

But do not be surprised if what stays with you in the years ahead is the random stuff. Just like the bears.

Stephen Blyth is Professor of the Practice of Statistics and managing director at the Harvard Management Company.