Time and change are the two powers that every human being has to deal with daily, and nobody has control over either of them. They are also the two components that are most difficult to manage.
The summary of your life is expressed in how you used time and change. Anything you become is a result of how you used your time and managed the changes that came along in your life.
You exist to fulfill a destiny, and you must do that within a specific period. Whether you fulfill that purpose or not depends on how well you use your time because you do not have forever to fulfill your purpose.