Anything you say before the word “but” does not count.

地图不是领土，但它是领土的指南。

人都知道说话可以显示自己的优点，但不知说话谨慎可以培养德性；人都知道饮食可以有益生命，却不知节制饮食可以养生。

The more you learn, the more you know. The more you know, the more you forget. The more you forget, the less you know. So why bother to learn?