Timmy, tired of Mr. Crocker's constant pop quizzes (in which he asks a question that no one can answer, or does not give enough time for people to answer) which everyone fails, wishes he has mind reading powers. He uses this to pass Crocker's pop quizzes and mess with his friends' heads. Unfortunately, Crocker figures his wish out, and uses an anti-mind reading helmet (which causes someone trying to read the mind of the wearer to read their own mind instead) as part of a new plot to capture his fairies.
The day begins at school in the closing hours, Mr. Crocker is about to let the children out for the day, the kids are literally poised at a race line about to take off, when Crocker suddenly screams "POP QUIZ!". He asks for the number of seconds in a year on Mars, A.J. stutters for a moment and then Crocker says "F's for everybody!" and pulls a rope, causing F marked papers to fall from the ceiling. At the cafeteria, Timmy asks Chester if Crocker is going crazy with the pop quizzes. Suddenly Crocker pops out of the lunch gruel and quizzes Timmy with a question, giving him no time at all to respond before he pulls another rope and rains down F's on Timmy again. At home, Wanda and Cosmo are helping Timmy clean up the pile of F's and one super F he brought home, when they suggest to him that if he could read minds then he would be able to tell whenever Mr. Crocker was going to give him a quiz.
Cosmo and Wanda grant the wish, and Timmy becomes psychic. When he tries to read Cosmo's mind though, he hears nothing but elevator music because Cosmo's head is empty. Cosmo then questions about a rattling noise that he hears when he shakes his head and Wanda then explains that Cosmo's empty head is good for carrying her stuff. Timmy is surprised to say that he cannot wait for school tomorrow. At school he easily outwits Crocker by reading his mind and finding out the answer to the pop quiz. Timmy is happy he got an A and reads the minds of his friends on their reactions, A.J. thinks he was lucky, Chester thinks he cheated, and Elmer thinks to himself that he hopes nobody will find out that his boil has a mind of its own. Later, Mr. Crocker pops out of Timmy's locker and tries to surprise him with another quiz, but Timmy knew the answer even before Crocker opened his mouth AND that Crocker's mother called him "Flippy". Crocker realizes the only way Timmy could know this and the answers to the tests before he could declare them out was because of his fairy godparents. At home, Timmy tells his godparents that he had a great day at school and the wish worked, although Wanda thinks that Timmy might use his powers to manipulate his friends and become a "big show-offy jerk", a thought that Timmy reads and takes as a suggestion.
First he uses his powers to defeat A.J. in a game. Timmy declares the square point that A.J. hoped Timmy wouldn't pick. A.J. then says "You've fragged my frigate!". Later at lunch, Timmy says hello to Trixie Tang but she asks "Why is this loser talking to me?". Timmy believes she is just saying that, but he reads her mind and she is having the same exact thought. His powers also affect Veronica who is staring at Timmy with hearts in her eyes thinking "Why isn't this loser talking to me?". The bouncer comes over and grabs Timmy, who reads his mind. The bouncer is wondering why he is working for ten year olds, and why he didn't finish college, then he thinks he can beat the answers out of Timmy. The bouncer tosses Timmy against a wall and into a can of trash. Meanwhile, Mr. Crocker has perfected his "Anti-Mind Reading Helmet", a clunky device that is so big that it requires sticks placed around him to hold his head up while wearing it, and when Crocker spasms about Timmy's fairies he breaks the support sticks and falls through the floor.
In the school hallway, Timmy runs into A.J., Sanjay, and Elmer. When he reads there minds, he learns they're planning a surprise birthday party for him. They quickly run off with the other students to the gym. Timmy is excited, but Wanda warns that it might be a trap and that it isn't even his birthday. Timmy tells them to wait near the gym so that he can use them in case anything goes wrong. At the gym, it turns out they had a party there after all... but Mr. Crocker was there as well. His Anti-Mind Reading Helmet dropped from the ceiling suspended by a rope onto Crocker's head, and now Timmy was unable to read Crocker's thoughts. Whenever he tried to use his power, it was reflected back at him and Timmy ended up reading his own thoughts. Crocker tells the children in the gym to think of their favorite color, the overload of thoughts is causing the satellite dish the wish installed on his brain to overload, and Timmy collapses as Crocker tries to goad him into admitting he has fairies.
Timmy struggles as he runs around the gym looking for Cosmo and Wanda, but Crocker had placed many different pink and green objects around the gym, confusing Timmy further. He finally manages to use his powers to tune into elevator music which he soon hears. When he realizes it is Cosmo, he rummages through a cart full of balls and finds Cosmo and Wanda disguised as basketballs. They unwish the wish and Timmy can no longer hear anyone's thoughts but his own. When Mr. Crocker tells Timmy to "Admit it!", Timmy agrees and admits to the students.... that it isn't his birthday, and that Crocker lied to get them to come here. They attack Crocker, demanding the candy he promised them. Francis grabs the rope holding Mr. Crocker's mind blocking device suspended and hoists Crocker up, Francis tells the other kids that Crocker is a piñata and that the candy must be in Crocker. They grab bats and whack Crocker as he screams. Outside the gym, Wanda asks Timmy "Are you thinking what I'm thinking?" and Timmy says "Nope, and that's just the way it should be!". Timmy is also surprised that Cosmo's empty head saved them. Cosmo's head opens up and he grabs candy from the hollow space in it, tossing it to Wanda and Timmy. Then Chip Skylark emerges from Cosmo's head and sings "Shiny Teeth and Me".