We master tools by using tools and we learn tools the fastest when they are relevant to us.

我们透过使用这些工具来精通工具的使用方法，而我们能最快地学会使用工具，就是在它和我们相关的时候。

I want to call attention to the means of mastering this curious and essential tool, and to land everyone who hears me to become discontented with his employment of it.

我想提醒大家注意掌握这个奇特而重要的工具的方法， 并让听到我的每个人都对他使用它感到不满。