Ted teaches a class to Barney about how to satisfy Robin in a relationship, and Marshall tries to get rid of his old barrel, Mabel.
Barney finds it hard to adjust into a serious relationship with Robin, as his bachelor impulses (fleeing after sex as if it was a one-night stand, not listening to Robin's problems and only talking to her when she's in the mood for sex) still take over. However, Barney starts to make uncharacteristically romantic gestures such as making Robin breakfast in bed (pancakes with Maple Syrup), which makes Robin suspect that Barney is cheating on her.
Marshall admits he knew the real reason behind the notebook and Barney staying late: Ted is giving lessons to Barney at his classroom in Columbia
This episode provides examples of:
- Attention Deficit... Ooh, Shiny!:Barney: They said I had AD...something. Can we have class outside?
- Double Take: When Robin arrives just in time for Ted to talk about her Blanket Tug O' War peeve, Ted asks Barney if he has any questions.Robin: Yeah, I have one.Ted: Yes, Robin.(Ted and Barney both Gasp! when they notice her, along with a regretful Marshall and Lily)
- Embarrassing Slide: Ted seems to have mixed up his pictures of Robin's drunk look and a Daniel Burnham building.Student: Uh, Professor Mosby?Ted: Yes, Susan?Student named Susan: That's a woman drinking beer on the toilet.Ted: (looking at the slides) Right. That-that was Daniel Burnham's wife. She was a troubled, troubled woman. We are moving on.
- Everything's Better with Penguins: Robin has a fondness of emperor penguins.
- Know-Nothing Know-It-All: Robin points out to Ted that some of the things he was teaching Barney were actually wrong, such as his belief that she gets turned on when her left knee is rubbed.
- Mistaken for Cheating: Robin assumes that Barney was cheating on her when he was trying to be a good boyfriend. Barney was actually taking classes with Ted.
- Nightmare Face: Robin's "Angry" face.Ted: Flared nostril ridges, wide unblinking eyes. If you ever, ever, see this face, Barney, run. And don't take a picture of it, she will punch you... And you will cry... For the third time... That night.
- Subject 101: The study of Robin.