Hyperbole
Deliberate exaggeration used for emphasis or effect, not meant literally.
Hyperbole overstates for impact, intensifying emotion, humor, or drama. Writers use it to stress how strongly a character feels or to satirize excess. Because it is obviously not literal, readers register the exaggeration as a signal of feeling rather than fact.
Example
The narrator’s claim that he can hear all things in heaven and earth is hyperbole that exposes his deranged, overheated sense of his own powers.
The Tell-Tale Heart · Edgar Allan Poe
See it in action
Analyses on StoryBites that use hyperbole: