Barney attempts to have a perfect week in which he scores a girl every night with zero rejections, but his reasons behind doing so are more than just pleasure.
Tropes:
- Cringe Comedy: Marshall and Lily end up in a huge case of embarrassment when they reveal to a couple they befriended and their own friends that they use one toothbrush. Even the imaginary Jim Nantz interviewing Barney in the small distant future is uncomfortable with this.
- Explain, Explain... Oh, Crap!: When Ted claims that he kept his toothbrush in the bathroom when he lived with Marshall and Lily, they all take a moment to realize they all shared the same toothbrush and react in disgust.
- Innocently Insensitive: Ted's story arc in the show is how he does not live down an incident in his Architecture class where believed that the name Cook Pu is a made-up name one of his students made up despite the fact that a Vietnamese girl keeps calling out "Here" whenever he says the name when he is reprimanding the students until Cook decides to leave in indignance. He really feels guilty over it.
- It ends up again in the final scene where he gets angry when the bartender at his bar says it and throws a fit about how dumb the name is, only to realize Cook Pu is present.
- Noodle Incident: When Barney tells Jim Nantz how Lily supposedly jinxed his perfect week, Nantz tells him that's one thing people aren't supposed to do, such as opening an email from Phil Simms in front of your kids.
- The Scottish Trope: The titular term "The Perfect Week" is this among the group. Not even Barney himself wants to hear it.
- Shout-Out: Robin's guy of the week is mentioned as "having a love/hate relationship with Gargamel."
- Tempting Fate: Lily ends up jinxing the Perfect Week when she says jinxes aren't real and Barney's potential final conquest ends up goggling over New York Yankees player Nick Swisher. She tries to atone for it.
- Marshall ends up jinxing Lily's atoning by saying that Jinx's aren't real and tries to atone for it as well by having him, Ted and Robin distract Swisher.
