One morning you awake to find the tooth fairy made an accounting error in your favor. She left $15 million under your pillow. Now you have some choices to make. Here is one: Would you continue to wake up each day and go to your current job?
We all have a certain amount of time to live. Every dollar we earn is given in exchange for time spent working. So whenever we buy a car or underwear or peanut butter we are paying in dollars but those dollars represent time. In a very real sense, buying stuff shortens your life. And btw that means a charitible donation is literally giving part of your life to another, taxes are the government redistributing life, national debt shortens the life of people of the future, etc, etc.
The most common response to this problem is: Find a job you love. This is good advice. The more pleasant your job is, the lower the opportunity cost. But think about the tooth fairy test. There arent very many jobs out there that are going to pass that test. And unless you love your job enough that you would do it even if you were financially independent -- then you are still selling away large pieces of your life.
There is only one escape: save enough money to live off the returns from your investments. Reach this goal and you will never again need to trade your time for food and housing.