Transformation: mastery. If you don't study, you can't study effectively.
The general idea of this sentence is: learning without integration, learning without effect.
This famous saying emphasizes that learning must be integrated, advocates a down-to-earth style of study, and opposes eating dates raw and not seeking deep understanding. Integration is an important educational principle, so Yang Wanli raised it to the standard of distinguishing between "learning" and "not learning", which really played a deterrent role. This sentence is short and accurate, which is the best explanation of cautious study style.