如俊法师 relates the story of how Master Ri-Chang used the cup to illustrate how much we don’t really know (the video starts from the 7 minute mark).
This teaches the lesson of how ignorant I am - to the extend of how I am not even aware of how much I don’t know.
How to remedy this?
To earnestly follow Buddha’s teaching to eliminate our ignorance.
I understand it as Bad karma would be like cold water. Good karma would be like hot water. A cup that has more hot water that cold water will feel warm. Similarly, we should strive to create more good karma than bad. This will have our good karma ripen first - likened to the cup feeling more warm than cold when touched.