10 Things You Don't Know About Matt Damon

March 1, 2010 — -- In "Invictus," Matt Damon plays Francois Pienaar, the captain of the 1995 South African rugby team championed by President Nelson Mandela. The Oscar nomination Damon earned for his performance was just one more distinction in a richly decorated Hollywood career, over the course of which Damon has been the subject of intense media focus.

There are still some things, however, you may not know about Damon. Here is a roundup of little- and lesser-known facts from the life of Matt.

Watch "Before They Were Famous," on a special edition of "20/20" Tuesday, March 2 at 10 p.m. ET

1. Damon's first foray into acting was as a kid in a commercial for TJ Maxx. Rumor has it that Damon earned $200 for the spot and spent it on a trip to New York to meet with a casting agent.

2. Damon and Ben Affleck have been friends since the third grade. As young teens, they got gigs together as extras in movies like "Field of Dreams." In the movie they appear in a crowd shot filmed at Fenway Park.

3. The Boston accent you hear from Damon in "Good Will Hunting" (1997) comes naturally, as the actor was born and raised in Cambridge, Mass. As an undergrad at Harvard, Damon perfected his accent at student-run productions, both backstage and onstage. Damon also tried his hand at musical theater while at Harvard.

4. Damon's big-screen debut came when he was just 18 years old, in the movie "Mystic Pizza" (1988). Damon only had one line, but he almost shared screen time with another Hollywood newcomer: Julia Roberts. The two appeared on the big screen together 13 years later when they were both cast in "Ocean's 11" (2001).

5. Damon played an anti-Semitic preppie in "School Ties" (1992). His co-star in the movie was Chris O'Donnell, and for years following the movie the two competed against each other for parts.

Matt Damon put Harvard on hold to act in "Geronimo." (Columbia)

7. Damon has risked his health for his career. For his role in "Courage Under Fire" (1996), the actor crash-dieted and lost more than 40 pounds in just over three months to play the role of Specialist Ilario, a drug-addicted Persian Gulf War veteran. Damon lost the weight by eating only chicken, egg whites, steamed broccoli and plain baked potatoes and running 12 miles a day. The rapid weight loss led to problems with his adrenal glands and doctors told him he was lucky his heart didn't shrink.

8. Damon and Affleck turned to a good friend, the actor-writer-director Kevin Smith, to help get their "Good Will Hunting" script noticed by the right people. At the time (mid-1990s), Smith was working for Miramax, and he was able to get the script into Harvey Weinstein's hands. But first, Smith used it for bathroom reading.

"I had [the script] at home," said Smith (in a video interview HERE). "I was living at this condo in Red Bank, and I took it into the bathroom to read the script. So I sat down, I'm a big bathroom reader, both in stature and in spirit. So I sit down and I read, and I'm a few pages in, and you're -- it's a page turner. Just gripped. Whole script without getting up. Pants down, read it from cover to cover, just never got up. Come out of the bathroom weeping, because it's a beautiful ending to that script."

9. Damon appeared in an uncredited cameo in Francis Ford Coppola's "Youth Without Youth" (2007). Damon has worked with directors including Steven Spielberg ("Saving Private Ryan"), Robert DeNiro ("Good Shepherd") and Martin Scorsese ("The Departed").

10. Damon says his favorite role to date is that of family man. He has been married to Luciana Barroso since 2005, and the couple has two daughters, Isabella and Gia. Luciana also has a daughter, Alexia, from a previous marriage.

Watch "Before They Were Famous," on a special edition of "20/20" Tuesday, March 2 at 10 p.m. ET