A deep well with a torn lining implies that all knowledge gained and heard becomes useless. It suggests that if the vessel for learning is damaged, everything acquired goes to waste.

This couplet uses a vivid image: "a deep well and a torn bucket." Imagine a well full of water, representing abundant knowledge or wisdom. But if your bucket is torn, you can't draw or hold any water. Similarly, the saying means that all the things you learn or hear become useless if you can't retain them, understand them, or apply them. It highlights that merely gathering information isn't enough; true learning requires the ability to internalize, remember, and make practical use of what you've acquired. Without retention, even the deepest well of knowledge won't quench your thirst.