Plot

While everyone meets Ted's crazy new girlfriend, everyone recounts their stories of how they met everyone else--but the stories turn out to have several inconsistencies.

Ted is telling his kids the story of a woman he met over the Internet in 2007 whose name he no longer remembers, so he refers to her as "Blahblah". Before meeting her, Barney believes that Blahblah is probably crazy, as are all women prowling the Internet for a hook-up--but that she is probably hot to overcome that craziness. After the gang meets Blahblah, Barney's assertions are strengthened. But in getting to know Blahblah and Blahblah getting to know everyone else, the gang discusses the first time each met the other. Lily and Marshall have told their story so often that they have it down to a fine art, but everyone else's story may have the same basic structure from both parties involved, but it's the subtleties that seem to differ. The story of Ted and Lily's first meeting is especially troublesome, and the true details which may never be totally known unless an impartial third party who may have been more lucid at the event comes forward.—Huggo

At the bar Ted introduces the gang to his newest girlfriend, whose name Future Ted can't remember and instead refers to as "Blah Blah" (Abigail Spencer). Embarrassed that she and Ted met online, she makes up a story about how she saw Ted across a crowded room at a cooking class. Barney theorizes that since BlahBlah is hot, she must also be crazy, as per the hot/crazy scale. A girl is allowed to be crazy, if she is equally hot. You want the girl to be above the Hot/Crazy line, also known as the Vickie Mendoza diagonal. It soon becomes clear that she is extremely neurotic and paranoid when she feels threatened by Robin. In order to change the subject, everyone begins to reminisce about how they all met each other, and their stories are told through flashbacks.

How Marshall met Lily - Marshall and Lily first met in 1996 when Lily needed help with her stereo and she had a strange feeling about room Hewitt 110. Knocking on the door, Marshall answered and it was clearly love at first sight. Blahblah suggests that Robin and Barney are together, eliciting 16 no's from Robin.

How Ted met Marshall - Ted and Marshall first met when they became college roommates. Marshall was "eating a sandwich" when he was told that the Dean was coming. When Ted arrived, Marshall attempted to conceal the "sandwich" and became upset that Ted (believing him to be the Dean) would be his roommate. The confusion was cleared up when Marshall walked in on Ted eating a sandwich of his own. BlahBlah feels that Robin was teasing her for never going to college and retorts that she was supporting her family and has a line of handbags coming out. Robin says there is nothing going on between her and Ted, which surprises Blahblah.

How Ted met Barney - Ted and Barney met in the men's room of MacLaren's in 2001, after which Barney made Ted his new wing-man and told a girl Audrey (Betsy Rue) that Ted is deaf so that Barney can get the girl's phone number. When the girl mentioned she knew sign language, Ted signed to her that Barney was a great guy and recommended she give him her number. After telling the story, Barney comments that he knew from that moment that he and Ted would be wing-men forever, even though the girl gave him a fake number. Ted reveals that he actually instructed the girl in sign language to give Barney a fake number, which upsets Barney. He reveals to BlahBlah that Ted and Robin dated for a while.

How Ted met Robin - Ted provides a condensed version of how he first spotted Robin across the bar in 2005, and the two instantly felt a connection.

Throughout the stories, Blah Blah becomes increasingly paranoid rather than mollified, particularly when she learns that the gang already knows that she and Ted actually met online and after hearing the story of how Ted and Robin met and dated for a while. When she wishes that she and Ted had a wonderful first meeting story like Lily and Marshall, Ted reluctantly counters that the story isn't as great as it sounds and tells the story of how he met Lily.

How Ted met Lily - During a freshman party at college, Ted and Lily met as Marshall chugged from a keg. He flirted with Lily and suggested that she come to his room, after which they began making out.

Ted explains that Lily had come to his and Marshall's room the next day and he and Lily have never spoken about their first meeting since. Blah Blah, keen to make Ted uncomfortable, vindictively orders Ted to confess to Marshall or she will. Returning to the table, Blah Blah asks Lily how she met Ted. However, Lily recounts the event differently.

How Lily met Ted - When Lily went to Marshall and Ted's room, Ted had been on the phone desperately apologizing to his long distance girlfriend Karen (Laura Prepon) for making out with another girl. After Marshall introduced her to Ted, Ted quickly rushed off upon seeing her to try sending Karen an email.

When Blah Blah presses for details, Ted takes Lily aside to discuss what happened at the party. Though Lily recalls kissing someone at the party, she can't remember who the guy was (Too much tongue guy) while Ted insists the guy was him (with unreasonably small mouth opening girl). Meanwhile, Marshall and Barney talk about how they met.

How Barney met Marshall - In 2001, Barney had attempted to persuade Marshall to forget his girlfriend and score with a random girl at MacLaren's. Marshall initially refused, but decided to play along when Barney unwittingly selected Lily as Marshall's target. Marshall had walked up to her and kissed her, which immediately impressed Barney until he learned that Lily was Marshall's girlfriend.

Unimpressed, Blah Blah tells Marshall that Ted and Lily kissed. Marshall doesn't believe the story, because he remembers that Ted and Lily had kissed two other people, not each other, at the freshman party, which Lily easily accepts. A furious Blah Blah storms out, but not before revealing that she met Ted playing World of Warcraft.

For the sake of Marshall and Lily's relationship, Ted accepts Marshall's story, though he is secretly unconvinced. At their college reunion in 2020, Ted is approached by a woman, Alexa Leskeys (Jolie Jenkins) who tells him that she was the one he made out with at the freshman party, proving Marshall was correct. Later Ted, Marshall and Lily all sit down for a "sandwich" that Marshall confiscated and get high when Ted suddenly realizes he can't find his wife.