You have a finite life, so use that time well.
A man asks you to give him ten hours of your life today to sell you cheap shampoo. There is nothing in this for you other than to listen to a boring sales pitch for ten hours on a brand of shampoo, and you will still have to buy it. Would you give that salesman your time?
Most would say no, but most do. A few years pass, and the advertisements have stolen ten hours of your time to sell you shampoo. It may seem only a two minute commercial break, but you gave it your time, and it adds up over time.
In these ways over decades the useless and the unwanted steal your time, a resource that could have been used in better ways to improve the quality of your life.
As a historian I look back over hundreds of generations. Babies seem to flow into ancient bones rapidly. Life flows fast. You blink, you are old; blink again, you are bones.
Guard who and what you give the time in your life to, it is finite and best used for those things that matter.