Yes, this is a common saying that suggests that people can be divided into two categories based on their approach to life: those who take action and make things happen, and those who simply observe events as they unfold.
People who watch things happen tend to be more passive and reactive, waiting for things to unfold before taking action. They may be content to let others take the lead, or may lack the motivation or confidence to take initiative themselves.
On the other hand, people who make things happen tend to be more proactive and goal-oriented. They are not content to sit back and wait for things to happen, but instead take action to achieve their goals and make a difference in the world.
Of course, this is a simplification and many people fall somewhere in between these two categories. However, the saying is a useful reminder that taking action and making things happen is often the key to success and fulfillment in life.