The scene in which Sheldon spanks Amy, Jim Parsons and Mayim Bialik both had a very difficult time staying in character, and several takes were ruined with them bursting out in laughter.
Sheldon mentions the Teenage Mutant Ninja Turtles (1987) theme song which producer Chuck Lorre co-wrote with Dennis C. Brown 25 years earlier.
Sheldon (Jim Parsons) reveals that his favourite cartoon theme song is from Teenage Mutant Ninja Turtles (1987)..."Turtle power," the infectious 90's anthem was composed by Chuck Lorre, the Big Bang Theory show runner and writer.
The scene where Penny was teaching the guys about fishing has her being the "manliest" in the demonstration. However, off-camera it was entirely the other way around. Kaley Cuoco was the grossed out one while the guys were way less so. Accordingly, between takes they held up a worm and chased her around the set while she was running and screaming.
First and last appearance of Meagen Fay as Bernadette's mother. Mrs Rostenkowski was first seen from above in The Countdown Reflection (2012), but she wore a big hat and was played by an uncredited extra.