誇大妄想

1. Origins, structure, and basic meaning

• Structure: 誇大妄想 is a noun read こだいもうそう, meaning a grandiose delusion in which one's status or abilities are believed to be far greater than reality supports.
• Basic usage: It can describe a fictional character gradually becoming consumed by such delusions or identify them as the subject matter of a play.
  • 小説の主人公は誇大妄想に取りつかれていく。 describes a novel's protagonist gradually becoming consumed by delusions of grandeur; 授業で誇大妄想を題材にした戯曲を読んだ。 describes reading a play about grandiose delusions in class.

2. Common pitfalls and similar expressions

• 取りつかれていく
  • ていく shows a gradual progression into the consumed state rather than a single instantaneous change.
• 題材にした
  • にした makes grandiose delusion the subject matter of the play; it does not state that the play itself is a real case.
• 誇大妄想 and 自信
  • 自信 broadly means confidence in one's ability, whereas 誇大妄想 describes a belief inflated beyond reality and is not a synonym for ordinary confidence.