flatter (oneself)

flatter (oneself)

To hold a vain, self-congratulatory, and exaggeratedly high opinion of oneself and/or one's achievements. Yeah, don't flatter yourself—she only asked you out to dinner because she wants to ask you about your brother. Gaston likes to flatter himself that he's the best man in town, but everyone knows he's just a pompous jerk.
See also: flatter