Break out the tissues. Robin Williams , who would have turned 65 today, touched many lives with his performances, humor, and character. Among those is Matt Damon, who took a moment to pay tribute to his Good Will Hunting co-star in a Reddit AMA session this week.A fan asked Damon about working with Williams, who won an Oscar for his performance, on the 1997 film."Working with Robin almost defies description," the Jason Bourne star responded. "He was one of the most generous, loving, wonderful people I've ever met. He had this capacity that I've never seen on a movie set. When everyone started to get tired and started to flag a little bit, he would launch into stand-up. We knew it was original because he was making fun of crew members and pulling them into these bits. It was like 15 minutes of the best stand-up ever that was just privately for us. Everyone would laugh and laugh and laugh and then everybody would get this boost of energy and go back to work."I'll never be able to thank him enough for what he gave us," the actor continued. "In my heart, that's where he is, as this person that I'm deeply, deeply grateful [who] came into my life and changed it for the better."