Future Ted explains how nervous he was his first day of teaching, when he was trying to figure out what kind of teacher he would be: formal disciplinarian or laid-back peer.
Before the first class, Marshall gives Ted the gift of a worn leather fedora and whip, just like fictional professor Indiana Jones.
Recalling his dream and deciding to take Barney's advice to not take any questions during the first class, Ted fails to learn from his students that he is in the wrong classroom.
When the real professor arrives and announces that the class is for Economics, a humiliated Ted races across campus to his correct classroom.
During a tuxedo-themed night at the bar, Barney explains you cannot get a woman wet (let her shower in your house), expose her to sunlight (date her before sunset), or feed her after midnight (breakfast together), or she will turn into your girlfriend.
Barney rushes to the arena and interrupts the New York Rangers "Kiss Cam" by ineffectually punching Brad in the face.