Here's how to understand it:
* Potato in a sack: This image evokes a sense of being hidden, unseen, or inactive. A potato in a sack is out of sight, not contributing to anything, and potentially going bad.
* Meaning: The phrase could be used to describe someone who is:
* Unseen and unimportant: They are not making an impact or contributing to anything.
* Passive and inactive: They are not taking initiative or doing anything to improve their situation.
* Not realizing their potential: They have the potential to do something great, but are hiding their talents away.
Example:
Imagine a talented musician who is afraid to perform in front of others. Their friend might say, "You're like a potato in a sack! You have such amazing talent, but you need to share it with the world!"
Important: Since this phrase is not standard, it's best to consider the context and the speaker's intentions when trying to understand its meaning.