: After feeling neglected by Leonard, Penny takes Beverly out for drinks. The legendarily uptight neuroscientist eventually loosens up over tequila shots, leading to a hilarious bonding session where she begins to treat Penny as her "home girl" .
: Sheldon objects to traditional Christmas decorations, instead hanging a bust of Sir Isaac Newton on the tree because Newton was born on December 25th, unlike the historical figure typically associated with the holiday. [S3E11] The Maternal Congruence
: This episode is notable for being the first of only two in the series where a main character— Raj Koothrappali —appears but has no speaking lines . : After feeling neglected by Leonard, Penny takes