Matt Damon, one of the most prolific but underrated actors of his generation, turned 50 years old Thursday.

American audiences have watched him grow up from the boy with the toothy smile to the now-revered Hollywood A-lister who has appeared with legends including Robert De Niro, Gene Hackman, Robert Duvall, Robin Williams and many more.

He’s also been in movies by nine different Oscar-winning directors, including Steven Spielberg, Clint Eastwood, Francis Ford Coppola, Martin Scorsese, Anthony Minghella, Robert Redford, Steven Soderbergh and Joel and Ethan Coen.

But Damon is perhaps best known for his longtime friendship with Ben Affleck, whom he has known for more than 40 years.

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Long before they were famous, the two grew up in the early 1980s just blocks away from each other in Cambridge, Massachusetts. Their parents introduced them in the neighborhood when they were about 8 and 10 years old, Affleck told Parade magazine in 2007. Affleck began to score his first acting gigs around this time and soon Matt was learning the trade, too.

On the brink of stardom

The classmates were inseparable and literally became an overnight success.

In high school they were known as “drama geeks” and regularly appeared in student theater productions. On the weekends, both would regularly catch a train or flight to New York City for auditions and bit parts.

By 1988, the boyish Damon got his first break, landing a role in the romantic comedy “Mystic Pizza,” which starred Julia Roberts. He was only 18 and was given just a single line of dialogue.

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The following year ,both appeared as extras in the 1989 film “Field of Dreams,” although neither received an acting credit, according to Insider.

Three years later, Damon and Affleck appeared as actors together for the first time in the film “School Ties” alongside Brendan Fraser. It was especially big for Damon, who was cast in one of the leading roles.

From there, Damon appeared in five more blockbuster films, with 1996′s “Courage Under Fire” earning him the reputation as a serious actor.

An early Oscar win

But he and Affleck didn’t become household names until the following year, with the release of the critically acclaimed “Good Will Hunting,” for which they both received the Academy Award for Best Original Screenplay in 1998. Damon was also nominated for best actor. Robin Williams took home the Oscar for Best Supporting Actor.

Damon was 27 years old then.

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The award opened the door on a historic Hollywood career that has endured for more than 30 years and produced some of the most memorable films.

Today, Damon is one of the most sought-after actors, producers and writers in Hollywood. He’s also an activist who co-founded H20, an organization that brings clean drinking water to developing countries around the world.

‘Six Degrees’ of Matt Damon

Damon has also been in so many films that some consider him the new center of the Hollywood universe.

His 67 film appearances has bested that of one of his contemporaries, actor Kevin Bacon, who has appeared in at least 64 films.

The slightly higher number of film appearances for Damon is noteworthy because Bacon’s name has been forever linked to the popular parlor game “Six Degrees of Kevin Bacon.” The object of the game is to link any Hollywood celebrity back to Bacon through their film roles like tracing a strand of DNA.

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Damon’s filmography includes many must-see films, including “Saving Private Ryan,” “The Talented Mr. Ripley,” the “Jason Bourne” franchise, “The Departed,” “True Grit,” “Monuments Men,” “The Martian,” and most recently: “Ford v Ferrari.”

But these few titles don’t begin to scratch the surface of cinematic depth moviegoers have witnessed from the veteran actor.

He received his star on the Hollywood Walk of Fame in 2007.

New movie coming in 2021

He has spent considerable time in Ireland this year filming his upcoming movie “The Last Duel,” about a knight in the Middle Ages who fights to the death to defend the honor of his wife.

Damon lives in Los Angeles with his wife of 15 years and his four daughters. He’s a big Boston Red Sox fan and has appeared in several World Series of Poker tournaments.

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Neither Damon nor Affleck has slowed down, even now that Damon has reached the half-century mark. By the way, Damon is 2 years older than Affleck.

Affleck won a second Academy Award for Best Picture in 2013 for the film “Argo.” After “Good Will Hunting,” Damon was nominated for Best Actor twice more for “The Martian” and “Invictus,” and he was nominated for co-producing the 2016 drama “Manchester by the Sea.”

Damon and Affleck are also the names behind the documentary series “Project Greenlight,” which launched in 2001 and provides financing to amateur filmmakers.

Early life

Matthew Paige Damon was born in Cambridge, Massachusetts, on Oct. 8, 1970.

He has an older brother Kyle, who is an artist.

His parents divorced when he was young and he was mostly raised by his mother, who was a strict disciplinarian, according to reports.

Damon was a student at Harvard University from 1988 until 1992, when he dropped out to take a role in the film “Geronimo: An American Legend.”

He was reportedly only 12 credits short of completion of his bachelor of arts in English and had been crafting the story of “Good Will Hunting” as one of his final class assignments. Four years later, he’d complete the script with his old buddy Affleck that would bring them Oscar gold in 1998.

During the acceptance speech, Affleck nervously said, “I just said to Matt, ‘Losing would suck and winning would be really scary.’ And it’s really, really scary ...”

The two have starred in 11 films together.

‘I want to apologize to Matt Damon’

Affleck and Damon remain friends.

Four years ago, Affleck hilariously snuck Damon onto the set of the “Jimmy Kimmel Live!” show by hiding him underneath a large coat he had on. About a minute into the interview, Affleck unbuttoned the coat, and Damon came out to cheers and laughter.

The three joked about a fake feud that had developed between Kimmel and Damon that endures to this day.

The feud began in the third season of Kimmel when the host ended one of his shows by apologizing to Damon for having to scrub his appearance from the episode because he ran out of time. The producer of the show found it so funny that Kimmel began repeating it every night, according to Time Magazine.

“We had a bad show …The guests were bad, and I was feeling pretty bad about myself at the end of the program,” Kimmel told NPR in 2013. “And I decided to say, for the amusement of one of our producers who was standing next to me…'I want to apologize to Matt Damon. We ran out of time'… And he got a kick out of it, the producer, so I just started doing it every night to amuse him.”

Kimmel explained that he chose Damon’s name randomly during his schtick.

“Matt Damon was just the first name that popped into my head. I was trying to think of an A-list star, and somebody we absolutely would not bump if he was on the show … The legs on this bit are unbelievable to me. I mean, people laugh every time I say it…Repeating the same joke every single night, you’d think eventually people would get tired of it, but they don’t.”

Kimmel now signs off every episode with the venerable phrase “I want to apologize to Matt Damon, we ran out of time!”

A fitting tribute to a Generation X celebrity who never seems to take himself too seriously.