Flash in the pan.
Flash in the pan.
'Flash in the pan' describes something that shows potential or success initially but fails to deliver anything further. The metaphor originates from mining, specifically the flash of a substance in a prospecting pan that looks like gold but turns out to be worthless. It’s used to caution against getting too excited about initial success without seeing sustained results.
His success was just a flash in the pan.
His success was brief and quickly disappeared.
The viral video was a flash in the pan, quickly forgotten.
The viral video's popularity was short-lived and quickly forgotten.
Her popularity turned out to be a flash in the pan and didn't last long.
Her short-lived popularity didn’t last very long.