I never imagined that at this stage of life I’d be spending Sunday afternoon in a classroom in Philadelphia, singing We Are Young.

But learning to sing a capella with Penn’s undergrad group “Off The Beat” was just the latest of many surprises for the 32 of us who came to Penn monthly since last September from around the world to study what’s right with human beings. – the grand finale of our master of applied positive psychology (MAPP) classes.

Mostly, we were surprised by the passion of our fellow students, exemplified over and over, for making the world a better place. One traveled from China, another from Jerusalem and another from Scotland every month for the rare privilege of learning from Martin Seligman and other luminaries in the field how to bring out the best in individuals, organizations and institutions. Two others, from Germany and Singapore, pulled up stakes for the year and settled in near the Penn campus. One simply added Philadelphia to a regular itinerary that already included China and London.

In a class intentionally mixed to represent diverse cultures, ages and domains, we so marveled at our good luck to be MAPPsters and teared up, when the director assured us at the opening session that admissions hadn’t made a mistake. “You belong here,” he said, along with “Trust the process,” which hung in our heads during an intense year.

In a discipline that applauds the value and vulnerability of human relationships, we gradually peeled ourselves back like onions during campus on-sites. At home, we drank gallons of coffee to keep up with reading that in the end was stacked nearly as tall as we were and write papers till no more words could come. And in this final session of a humanities class (still more papers to come), we learned from an undergrad a capella group how to become a musical hive.

Although I have felt very old on a few morning after only a few hours sleep, the stimulation of a year with such impassioned positive thinkers makes We Are Young seem right at any age. And the refrain, I really don’t want to get out of my head:

“Let’s set the world on fire. We can burn brighter than the sun.”