Presidential candidate and Vermont Senator Bernie Sanders made an appearance on The Late Show last night to talk through Trump, the 1%, and young people’s desire for change in this country. He also turned in a comic bit interrupting Colbert’s opening monologue. But the most significant thing that happened during his interview was Sanders’ unfortunate gaffe in its first minute, which mitigated the effectiveness of his appearance.

Colbert said, of Sanders’ impressive win in the New Hampshire primary: “You won by 22 points, but you also won some interesting categories. You won 86% of people 18 to 24. It’s like you’re Puppy Monkey Baby.

Sanders laughed heartily. But when asked if he got the reference, Sanders replied, bashfully: “Actually not, no.”

Fast-forward 30 seconds in:

Hmm, if Bernie is the candidate that is supposed to speak to the interests of young people, this is cause for alarm. PuppyMonkeyBaby, as Colbert implies, is an icon of Super Bowl commercials and #random advertising in the thick of the millennial age. The CGI imp is the central, mystical, inexplicable totem of our troubled, meme-addled generation, and he markets a Mountain Dew energy drink. Get with it, Sanders, or you might lose some of that vote that has the potential to pave your road to the Democratic nomination.

Colbert gets it. “Listen, no one knows what it means,” he responded to Sanders’ bewilderment. “It’s complete nonsense.” That’s right, Stephen. It’s a canvas for our collective cultural imagination.