WATERVILLE -- History teacher Mark Pelletier spoke of happiness to graduating Winslow High School students Wednesday night, during the school's 107th commencement exercises.

But Pelletier could not have been more serious. Today's society, he said, places too much emphasis on the moment.

"Pleasure in the present does not lead to happiness," the 1987 Winslow High graduate said. "No one looks back at the pleasure of that scoop of ice cream."

Pelletier also spoke of the "epidemic of depression" in industrialized nations and among the wealthy. College students are depressed, stressed and overwhelmed, he said.

Interest in a course on happiness at his alma mater, Harvard University, has skyrocketed, Pelletier said.

For the solution, Pelletier referenced the works of Martin E.P. Seligman, a University of Pennsylvania professor whose works focus on helplessness, depression, optimism and pessimism, and on positive psychology. Pelletier named Seligman's 24 signature strengths, and advised the class of 2009 to focus on theirs.

"Choose work that lets you use your virtues every day," Pelletier advised. "Choose a spouse whose strengths bring out your best virtues. But remember, you're not supposed to be happy all the time. Life's ups and downs bring out happiness."

Pelletier closed by naming forgiveness as the most important signature strength.

"It takes courage," he said.

Perhaps unknowingly, class vice president Jessica Breton, the mistress of ceremonies, provided a segue for Pelletier's speech.

"Remember, we learn more from our mistakes than we do from our successes," Breton said.

Class president Kevin Martin lent some levity to the ceremony. Reading from a poem he wrote, Martin provided classmate Joseph Jean Marc Dupuis III with a moment of fame.

"Joey Dupuis is destined for fame," Martin said. "He gave me five dollars to mention his name."

Martin said that, as graduates, his classmates can use cell phones when they want, go to the bathroom when they want and call teachers by their first names. But he reserved praise for those who saw them through the past four years.

"Don't forget those sitting in the chairs and bleachers," Martin said. "Let's give a round of applause for parents and teachers."

Superintendent Hugh Riordan, Principal Douglas Carville and athletic director Sean Keenan gave out diplomas.