The phrase “daddy knows best” is often used to describe a situation in which a father figure is seen as the ultimate authority and decision-maker. This can be a positive or negative thing, depending on the context. In the case of SpongeBob SquarePants, the phrase “daddy knows best” is often used ironically, as SpongeBob’s father, Harold SquarePants, is frequently shown to be wrong or out of touch.
One example of this is in the episode “The Bully,” in which SpongeBob is bullied by Flats the Flounder. Harold initially tells SpongeBob to ignore Flats, but this only makes the bullying worse. Eventually, SpongeBob stands up to Flats and defeats him, proving that he doesn’t always need to listen to his father.