PlotSheldon's obsession with gift-giving etiquette drives his friends crazy. Meanwhile, Penny starts dating a handsome colleague of Leonard's.
- Always Someone Better: Dave Underhill to Leonard. Not only is he smarter and more accomplished, he's also tall and handsome. Subverted when Leonard finds out from Penny that he tried to take nude photos of her, and is married on top of that.
- Christmas Episode: The first in the series. It establishes that Sheldon doesn't celebrate Christmas.
- Green-Eyed Monster: Leonard is clearly jealous of Prof. Underhill for dating Penny.
- Hypocrite: Leonard is dismissive of Dave, but gushes at him asking to work with him, even giving him all the phone numbers he needs to reach him like a lovestruck girl. Lampshaded immediately afterwards.Leonard: What? You've never seen a hypocrite before?
- Out-of-Character Moment: Sheldon is so excited at getting a napkin signed by Leonard Nimoy that he gives Penny a hug (albeit a very awkward one).
- Serious Business: Sheldon hates getting gifts because then he feels obligated to give one of equal value in return, which he finds difficult and time consuming.