FAIRFAX, Va. – Ben Affleck cracked jokes about his film career during a high-school commencement speech Friday while giving a heartfelt tribute to a graduating student he befriended years ago.

“Everything I learned about life that really matters … I learned from Joe,” Affleck told the audience.

Kindregan suffers from ataxia-telengiectasia, a rare, degenerative genetic disease. Over the past decade, Affleck has helped Kindregan raise money to develop a cure for the disease.

The close nature of the pair’s friendship was evident at Friday’s ceremony; Affleck planted a kiss on Kindregan’s forehead after being introduced and later playfully swatted him with a rolled-up program.

The two met in 1998 when the Kindregans came to Dulles International Airport to watch a crew shoot the film “Forces of Nature,” which starred Affleck. The actor noticed Kindregan, then 10 years old, in his wheelchair and struck up a conversation.

Affleck jokingly explained to the 284 graduating seniors — who most likely never saw the film — that “it was very similar to another movie called “Citizen Kane.’”

Affleck said Kindregan has since been on the set of all of his films — “He liked being on the set of `Daredevil’ a lot more than being on the set of (box-office bomb) `Gigli.’ But he was too polite to mention it,” Affleck said.

Kindregan introduced Affleck to the audience by saying “He is married to the cutest girl (Jennifer Garner) … but most important he is the best friend you could ever have.” Kindregan declined to be interviewed.

Affleck, dressed in a traditional graduation gown, sat on the dais next to Kindregan and other school officials and shook hands with students who came up on stage to receive their diplomas. A few were bold enough to ask for a hug, and Affleck obliged.

“He’s a good hugger,” said graduate Melinda Wodatch. She said Affleck’s presence added to a memorable event. “I think all the kids were actually listening to his speech,” she said.

Garner attended the graduation but did not participate in the ceremonies.