A Needle in a Haystack

Meaning:
Something or someone that is difficult and nearly impossible to find.

Example:
Trying to find a lost child during the IT fair would be like searching for a needle in a haystack!

Did you know?
This phrase originated even before Shakespeare’s time. Initially, it was called “a needle in a bottle of hay”, “bottle” being an early expression for “bundle”. It has proliferated throughout centuries as it paints a near perfect picture of a near-impossible task.