Season 3, Episode 1 - The Electric Can Opener Fluctuation
Aired September 21, 2009
After the gang return from their Arctic expedition, Sheldon is stunned to learn that the guys manipulated his data and invalidated his research. Fearing his scientific reputation has been ruined, Sheldon retreats to his mother's house in Texas. Meanwhile, Leonard catches up with Penny after his summer away, but just as it seems like a relationship is about to start, Leonard must fly to Texas to bring Sheldon home.
Season 7, Episode 21 - The Anything Can Happen Recurrence
Aired April 24, 2014
Sheldon tries to be more spontatenous and decides to bring back Anything Can Happen Thursday, leading to him spending the evening with Penny after she is angered by Amy and Bernadette. Meanwhile, Raj gets advice from Howard for his upcoming date with Emily.