By 2004, Matt Damon was already a major Hollywood star with his storied CV including the lead role in The Bourne Identity (2002), a key character in Ocean’s Eleven (2001) and a Best Original Screenplay Oscar for Good Will Hunting (1997), which he starred in, and co-wrote with his childhood friend Ben Affleck. So he really didn’t need to make a surprise guest appearance as a punk singer in trashy ‘teen sex comedy’ EuroTrip. But we’re glad that he did.
For those who may not be entirely au fait with the plot of EuroTrip,. one of many vaguely raunchy Noughties films aiming to get a slice of the American Pie er, pie, the narrative begins with dorky teenager Scotty Thomas (Scott Mechlowicz) being dumped by his high school ‘sweetheart’ Fiona (Kristin Kreuk) following his graduation.
As if this were not sufficiently depressing, Scotty then attends a graduation party where he, all his classmates, and possibly every other high school senior within a five mile radius, learns that his now-ex girlfriend has been cheating on him for the past year with the lead singer of a local punk band: this he discovers because said singer, Donnie, has written a song celebrating the many sexual encounters he has been sharing with “the nastiest, freakiest, little sexpot I know”, sensitively titled Scotty Doesn’t Know. Cue a tattooed, pierced, tongue-waggling Matt Damon gleefully delivering lyrics such as “I can’t believe he’s so trusting / While I’m right behind you thrusting / Fiona’s got him on the phone / And she’s trying not to moan“.
Poor Scotty.
Eurotrip (2004) – Scotty Doesn’t Know – YouTube 
Damon’s cameo is arguably the very best thing about EuroTrip, and his participation in the film baffled just about everyone who saw it, and indeed the millions more who didn’t, and never want to.
The reason why Damon took the role is actually very wholesome. Quizzed about it during a Reddit AMA (Ask Me Anything), the actor revealed that he signed up because the film’s screenwriters, Jeff Schaffer, Alec Berg and David Mandel were his friends at college, and by an extremely happy coincidence he was scheduled to be in Prague working with Heath Ledger on The Brothers Grimm – director Terry Gilliam’s follow-up to Fear And Loathing in Las Vegas – at the same time that Schaffer was directing his shoot for EuroTrip in the Czech capital.
“Alec and Dave and Jeff were making EuroTrip and they said ‘Will you come play this [Henry] Rollins kind of insane, bad version of a suburban punk band guy?’ And I said, Yea, I’m in Prague.” Damon told Redditors.
“So I showed up and I’m sitting there, and I’m like, I’m wearing a wig, just shave my head, let’s just go for it, and we did it, and put a bunch of piercings all over. And ‘Scotty Doesn’t Know‘, the song, was actually written by one of my college roommate’s brothers, and… one of my college roommates… Jason, is playing guitar in that group. So it was kind of a family affair.”
Matt Damon, ladies and gentlemen: one of the good guys.
But is this EuroTrip cameo Damon’s finest music-related acting role we hear you ask? Well, actually, no, that would be this one…