[Note: I wrote this with an audience of college-aged young adults in mind, though I think the principles here are applicable to all human animals.]

Imagine putting 1,000 marbles into a big jar. Imagine removing one marble each month.

Those 1,000 marbles are the months you have. Those are all of the months you have, from the moment you are born until the day you die, on average, at age 80. That’s all you get. Time is non-replenishable, so you need to use it wisely or it will disappear in a flash without leaving you any notable memories.

And it’s worse than you might think because you need to pour 240 of those marbles out right now! You have already used them up because you are about 20 (x 12 month per year). Here’s more bad news: You might not make it to 80 in good shape. You might start showing signs of dementia at 65. You might be wheelchair bound at age 56 after getting into a car accident.

Did you remember to remove a marble from the jar on July 31? That was two weeks ago. That was the end point of another month. How quickly did July go by for you? Probably like a snap of your fingers, right? What did you accomplish in July? If you wrote down all the important and meaningful things you did in July, how many of those things could you write? When you get to be in your 40s or 50s, time will speed up dramatically. When you are middle-aged, which will happen soon, the marbles will be virtually pouring out of your jar.

The best way to slow down the treadmill is to create memories and meaning. This is not done by letting life merely happen to you. This can only be done mindfully, with effort. The best memories are those that are anchored by deep relationships, but you cannot make an old friend. You can only make new friends, cultivating them over time through listening and interacting mindfully and by recognizing embracing the challenges of relationships when it is a healthy thing to do. We can then celebrate the mutually experienced joys with our friends as largely undeserved gifts. That’s because despite our efforts, excellent friendships, to the extent that we are lucky to be part of them, are lavished upon us by forces beyond our control. When they happen, good friendships are the only possible foundation for what can matter in our lives. They are the basis for creating the kinds of memories that can slow down the treadmill and make our journeys memorable and meaningful.

You can take what I am writing as a threat or a challenge or both. You are not immortal, so you shouldn’t compare yourself to immortal gods. Instead, you should compare yourself to the people who never had the opportunity to be born. You have been given a great gift: A chance to live a life. Now, you have a choice about how you are going to live your life. You could fritter it away on social media, playing video games, having shallow relationships with other people, or indulging in an addiction.

Or you can mindfully celebrate life every day. You can do amazing things if only you treat each month like the extraordinarily precious thing it is. And when you remind yourself about the precariousness of life, you might come to the same conclusion that I have come to: Why do anything unless you do it well? You might conclude: Why do anything at all unless you are going to make it a quality experience that results in an excellent memory for you and the people you truly care about?

If these things ring true to you, you might conclude, “I need to use all of my remaining months well.” At the end of each month, you’ll want to conclude: “That was a marble well-spent!”