The story behind How I Met Your Mother's most — wait for it! — legendary line

The story behind How I Met Your Mother's most legendary line is even more awesome than you might think.

When Barney Stinson (Neil Patrick Harris) tries to convince Ted Mosby (Josh Radnor) that they need to change things up instead of always going to same bar in season 1's "Sweet Taste of Liberty," he gets an idea: they should pick up (as in, pick up) women at the airport instead. "It's going to be legend — wait for it, and I hope you're not lactose intolerant because the second half of that word is — dary!" he confidently exclaims while Ted is on the phone with Marshall Eriksen (Jason Segel).

It's one of the long-running comedy's most iconic quotes, yet HIMYM creators Craig Thomas and Carter Bays can't claim it as their own. "That script was written by Chris Miller and Phil Lord, who have gone on to do a few things since then," Bays jokes to EW for our roundup of 30 perfect TV punchlines. Before the award-winning, box-office-crushing filmmakers made critically-loved movies like Spider-Man: Into the Spider-Verse and The Lego Movie, they were producers and writers on the first season of the CBS comedy, and this was the first episode they wrote.

That's why Bays and Thomas are still jealous of how Lord and Miller, who exited the series after that first season, were the ones to craft this deeply layered demand — they came in, wrote one of the most fan-favorite jokes of the entire series, and then left. "Sadly, Chris and Phil’s career has been a long, downward spiral since that moment," deadpans Thomas. "They’ve really done nothing else since leaving How I Met Your Mother."

Interestingly enough, the line itself went against a mandate that the showrunners had tried to enforce for Barney after his "Wait for it!" catchphrase was established in the series premiere. "We both felt very strongly: 'Let's not turn Barney into the Fonz, and let's not make him a guy who does a bunch of catchphrases,'" Bays says. Adds Thomas: "Let’s not s--- on Fonzie here!"

"But we held onto that for, like, five minutes and then that went out the window," Bays continues. "He's actually based on a friend of ours, and the idea of a catchphrase is real life because there are just some people that recycle the same thing over and over again because it works for them. And Chris and Phil were the ones who said that he needed some sort of metric by which to measure things, some word that describes the peak for Barney. What's the best of the best?"

That's when Lord struck comedy gold, creating what would become Barney’s series-long signature catchphrase "legendary" — first heard (and repeated 12 times!) in this episode, which aired 15 years ago this month. "In some weird way, Barney is aware he's in a story being told in the future, creating stories that will be told for generations," Thomas explains, noting that he was also partially inspired by A Christmas Story’s future narrator. And elsewhere in this episode, Bays had already decided that Barney wants to lick the Liberty Bell that night, so Lord just followed his lead when coming up with the "aspirational" catchphrase. As for how he landed on the word "legendary?" "I didn’t really understand how weird that was and I think I was just trying to make sense of it all," Lord says with a laugh.

For this specific "legendary" moment, Lord thought to combine both of Barney's catchphrases, which Bays says was "like the old Reese's Peanut Butter Cup commercials, getting chocolate in the peanut butter: it’s two things coming together perfectly." Then Miller decided to milk the joke even further when he saw the perfect opportunity just waiting for him. "Phil had written 'legendary' into a lot of the pages of the script and when I got to the one that was 'legend — wait for it — dary,' I added 'legend — wait for it, and I hope you're not lactose intolerant — dary,'" Miller says. "I just thought, 'dary' is sitting out there all alone on an island. So I was like, 'Here we go!'"

"What is this preoccupation with lactose, Chris?" Lord asks with a laugh, calling out the fact that he's noticed lactose intolerant jokes are actually a long-running trend with his writing partner. "Well, listen, some of us, it makes us a little gassy, I’m not saying who," responds Miller. "This is a classy publication."

But Thomas and Bays ultimately (and literally!) got the last laugh; they added "the second half of that word is … " to make the gag even longer. "This was episode 3 and this was already an incredibly long, clunky, intricate joke on purpose," Thomas says. "It’s this labyrinth of a sentence. That was our twist on it — make it tortured right away." Adds Bays: "It really should have been the season 7 version of the sentence."

Despite (and because of) how complicated the quip became, Thomas remembers how "that line killed and got a huge laugh from everyone on set" when Harris delivered it. And it would go on to be one of the most quoted moments of the entire series, cementing its legendary status. "God bless Chris and Phil," Thomas sighs.

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