We already know the actor went on to become a superstar who immortalized the words "All right, all right, all right," but thanks to the wonders of the Internet, we can watch the magic begin during his tryout for the film.
A video of McConaughey's audition is making the rounds in honor of the Criterion release of the 1993 Richard Linklater film. There's the young actor looking majorly relaxed (he is playing a stoner, after all) and tossing off lines like "That's what I love about high school girls, man. I keep getting older, but they stay the same age."
Here are some other stars who also set out to wow casting directors with their takes on characters.
De Niro didn't snag the role of Sonny Corleone (that went to James Caan) in the epic film, but we suspect that director Francis Ford Coppola saw something he liked in the then-lesser known performer, as De Niro was cast as the young Vito Corleone in "The Godfather II."
Scarlett Johansson's 'Jumanji' audition
Even as a little girl, Johansson had star power and beauty. She makes going out for the role of Judy Shepherd look effortless (though the part eventually went to Kirsten Dunst).
Jimmy Fallon's 'SNL' audition
"Saturday Night Live" made him a star, and now he's a big-time talk show host. But years ago, Fallon used his celebrity impressions of stars like John Travolta, Jerry Seinfeld, Chris Rock and Adam Sandler to get his foot in the door.
Chris Colfer's 'Glee' audition
Colfer slayed when he tried out for the role of Kurt Hummel. You can hear the delight in the room when he sings "Mr. Cellophane."
Gabourey Sidibe's 'Precious' audition
This one is pretty deep. Sidibe shows off her acting chops as she reveals, in character, that she is HIV-positive.
Mark Hamill's 'Star Wars' audition
It now seems incomprehensible that anyone but Mark Hamill could have played Luke Skywalker in "Star Wars," but who knows what would have happened had he not done as well in his 1977 audition.
Rachel McAdams audition for 'The Notebook'
You'll probably have a better reaction to McAdams' tryout for "The Notebook." The film made her a part of pop culture, but the actress cringed when "Today's" Matt Lauer surprised her with her audition tape.