Written by series co-creators Chuck Lorre and Bill Prady, with Steve Holland, Steven Molaro, Dave Goetsch, Eric Kaplan, Maria Ferrari, Andy Gordon, Anthony Del Broccolo, Tara Hernandez, Jeremy Howe and Adam Faberman.
The show ends when the gang is eating in Apartment 4A (an allusion to the final scene in the opening credits) with Sheldon and Amy wearing their Nobel Prize medals, as a melancholic acoustic version of the theme song's chorus slowly plays.
Steve Holland said that the writers were aware of fan expectations about the finale, but aimed to write what "felt right" to them—in particular, the idea that there was a "big emotional climax" after which the characters would "get up and go to work together", with their lives continuing as normal.
When the writers realized that Raj would not be seated next to anybody on the plane, Chuck Lorre suggested it would be a good opportunity for a celebrity guest star.
[5] It received a 3.2 rating and a 17 share in the 18–49 demographic, and aired at 8 p.m. alongside Grey's Anatomy on ABC, Superstore on NBC, Paradise Hotel on Fox and iZombie on The CW.
However, he criticized that the finale "didn't know what to do with Raj", that it did not sufficiently explore Penny's changed mind over having children, and that Sheldon's speech had ambiguities of being "a dream or hallucination".
Gajjar saw Amy's speech as one of a few "rare moments" in the show that "let shine the importance of women in science", found the working elevator to be the most surprising development in the episode, and criticized that Raj's narrative lacked closure and Penny's "sharp turn" to wanting children was undeveloped.
He said that it reflected how the show developed, through the addition of "key female characters" and "more grown-up problems and issues", without abandoning the focus for nerdy topics.