The episode is framed by a special installment of titled Behind the Flags: A Retrospective .
: Howard and Raj return to provide the theme music, adding a theatrical flair to Sheldon and Amy’s vlog. [S10E21] The Separation Agitation
: The retrospective includes interviews with Leonard and Penny about the show's origins, though Leonard humorously struggles to remember any "magical" moment when the series began. The episode is framed by a special installment
: The "agitation" of the title is literal; Howard and Bernadette find it so difficult to stay away that they (along with Stuart ) repeatedly check in on the baby, eventually leading them to skip work entirely to watch her through the daycare windows. Bert’s "Rich" New Romance [S10E21] The Separation Agitation