The unreliable narrator of The Secret Diary of Adrian Mole, Aged 13 3/4, Adrian, is, as the title states, 13 and 3/4 years old, and he is disappointed in those around him. He wishes more people were intellectuals like himself, even writing to Malcolm Muggeridge, a writer, for advice on being an intellectual. In actuality, he is out of touch with the realities of life around him. His mother, Pauline, is clearly having an affair with the next-door neighbor, Mr. Lucas, and yet Adrian is only aware that Mr. Lucas is at their house a lot and his wife seems to do a lot of the major chores around their house. Even when Mrs. Lucas leaves Mr. Lucas, Adrian doesn’t see what is happening.

Adrian’s father, George, and his mother begin to fight even more until his mother takes off with Mr. Lucas, leaving Adrian to care for his father. George struggles with money and is at a loss until he takes up with a coworker, Doreen Slater.

Adrian’s best friend is Nigel. Nigel’s family is rich, and although this bothers Adrian on some level, he doesn’t really know why. When Nigel goes out with Pandora, the new girl at school whom Adrian likes, Adrian becomes angry at Nigel and bereft at the imaginary loss of Pandora. Adrian and Pandora are friends and, at the encouragement of Pandora, begin a literary magazine.

One of Adrian’s biggest allies is his grandmother; she even deals with Barry Kent, the school bully, for him! Adrian also befriends Bert Baxter, an elderly man Adrian meets through a school group. At first Adrian isn’t very fond of Bert, but he grows to know and like him. There’s also John Tydeman, who encourages Adrian after reading poetry Adrian has sent to the BBC (although he does reject the poetry). It is this entire cast of characters which contributes to Adrian maturing throughout the book.