* Something has great potential, depth, or resources. This is often used in the context of knowledge, talent, or wisdom. For example, "Her knowledge of history runs deep."
* Something is not easily exhausted or depleted. This refers to the fact that a deep well has a large supply of water. For example, "His creativity runs deep, he's always coming up with new ideas."
The proverb itself is often associated with:
* Patience and perseverance: It takes time and effort to reach the deep water in a well, just as it takes time and effort to achieve a deep understanding or mastery of something.
* The hidden potential within oneself or a situation: What appears simple or shallow on the surface may have much more to offer beneath.
The phrase is a reminder that things of true value often require exploration and effort to discover and appreciate.