The Platinum Rule: 1. Attraction, 2. Bargaining, 3. Submission, 4. Perks, 5. The Tipping Point, 6. Purgatory, 7. Confrontation, 8. Fallout. Ted adds a ninth step: Coexistence.
This episode has the maximum degree of 5 of nested storytelling in the entire show. A story (Barney's) within a story (Lily and Marshall's) within a story (Robin's) within a story (past Ted) within a story (Future Ted's).
In any scene where the gang is eating Chinese food, Barney Stinson is shown to be very bad at using the chopsticks. The only time he is ever shown able to use chopsticks is in Season 3 on the couch and in Season 7 at the Hibachi Grill Restaurant.
In the season 2 episode "Brunch" Ted's parents come to visit and Ted's dad hooks up with Wendy the Waitress and Barney is mad because he "cock blocks" him. But in this episode Barney hooks up with Wendy in 2005. Barney has stated multiple times he doesn't date a a girl again.
Catchphrase: Barney uses "So just. Okay?" for the second time.