Region: General | Usage example: That viral hit was a flash in the pan; no one remembered it a week later.

Flash in the pan

Meaning

A brief and disappointing success or occurrence.

Warning against putting too much stock in short lived success.

Origin notes can vary by region and source; this page gives the commonly reported explanation and usage context.

Muskets flashed without firing when the powder in the pan ignited but the shot failed.

Seventeenth century musket term adopted into everyday idiom.