10 Things You Don't Know About Matt Damon

"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").

Matt Damon and wife Luciana Bozan Barroso arrive for the screening of "The Informant!" at the Venice film festival, Sept. 7, 2009. (Damien Meyer/AFP/Getty Images)

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