The line comes from Pixar's 2004 film The Incredibles, spoken by the neighborhood boy on a tricycle who watches the Parr family and other heroes in action. His short, awestruck reaction became one of the movie's most quoted moments because it sums up how the audience is supposed to feel. Shared widely as a reaction clip and soundboard staple, it is now used far beyond the film to mark anything impressive, surprising or cool that deserves an enthusiastic response.