As Sheldon and Leonard work on an equation, Sheldon finds himself humming a song, but he can't figure out what it is.

Amy calls the guy she was dating to see if he wants to go out with her again.

Raj tells Howard he's made a Facebook page for their band, and Howard is upset that he wasn't consulted on it.

Sheldon continues to try to figure out the song, but he has no luck.

Amy tells Bernadette about her date, and Bernadette is surprised that she's planning something intimate.

Penny and Leonard argue over who has to take care of Sheldon as he tries to figure out his tine in the middle of the night.

Sheldon is convinced that he's going crazy, so he starts videoing his life.

Sheldon finally remembers the song, which is a Beach Boys classic.

Howard and Raj go to a coffee shop to find their one fan. They then realize that the person they thought was a very cool fan is actually kind of gross.

Sheldon realizes the song that was in his head was about Amy, and he goes to see her, interrupting her date.

He tells her that he wants to be her boyfriend, and he tells her he loves her. They share a kiss, and all is right with the world!