You can't manage what you don't measure.
The past is a foreign country; they do things differently there.
高尔夫是一个没有答案的谜题。我打了50年高尔夫,却仍然对如何打好它毫无头绪。
You can’t change the past, but you can shape the future.
Learning is any change in a system that produces a more or less permanent change in its capacity for adapting to its environment.