updated 06/18/2007 AT 01:00 AM EDT
•originally published 06/18/2007 AT 01:00 AM EDT
Affleck's friendship with Kindregan, 19, goes back almost a decade. In 1998, Kindregan visited the set of Forces of Nature, which was filming at nearby Dulles Airport. Kindregan, who has ataxia telangiectasia (AT)—a degenerative disease that causes loss of muscle control, cancer and immune-system failure—"wasn't like other kids," Affleck told the audience. "He was on a mission." Enlisting Affleck's help in his drive to raise research funds to find a cure (people with AT rarely survive their 20s), Kindregan "made it to the set of every single movie I ever made," said Affleck, 34. "If that were me, because I am not as strong as my friend, I think I would have had a much harder time fighting uphill.... Everything that I learned about life that matters, I learned from my friend."
Kindregan's special day didn't end there, as Affleck and wife Jennifer Garner joined Joe's family and friends for his graduation party—a green-and-gold-themed (his school colors) barbecue. "This was a big milestone for Joe and a big celebration," says his mom, Suzi. "He was very happy to share his friends Ben and Jen. Joe said it was the best day of his life."
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