The author William Irvine (whose book, A Guide To The Good Life, is a great introduction to Stoic thought) shared the Stoic formula for happiness in this post on Stoicism Today.

Here’s the formula: X = the number of days you have left to live

It’s not exactly a formula, just a reminder that each of us has a finite, unknown number for X. Keeping this thought in mind daily, knowing the end of this day reduces X by 1, can offer perspective that makes each day richer and more meaningful.

Irvine goes on to suggest another helpful formula: X = the number of times you will do something in the remainder of your life

You have X number of times left to call your mom or kiss your love or hug your kid or eat Green & Black’s organic 85 percent cacao dark chocolate.

As you do a thing, if you for a moment imagine it might be the last time you do it, you will experience it more mindfully, more vividly. It turns autopilot off, even if for just a second or two.

I took my daughters to the swimming pool yesterday. As they were clamoring for me to jump in and join them, I paused at the edge of the deep end of the pool, my toes poised on the edge of the warm cement, and imagined this would be my last time ever jumping into water. And then I stepped off and truly saw my feet splash in first and felt my body drop into the cool water and the delightful sensation of floating. The slight sting in my nose and eyes. The feeling of defying gravity for a moment. It was a joy. And, of course, it wasn’t the last time. I jumped in several times yesterday, but the only one I can recall clearly was the first jump which I had imagined as my last jump ever.

I think even a small moment here and there thinking in this way could have a big impact on your daily joy.

And as Irvine suggests in his post, it can encourage you to create more moments worth savoring:

And there is another important thing to realize about the above formula: you probably have it in your power to turn X into X+1! You need only go out of your way to do something one extra time. At this very moment, there are X more times you will kiss the person you love. But if, as the result of reading this, you go give him or her a kiss that you otherwise wouldn’t have given, you will increase this number to X+1. And chances are you will have fun doing it!