We’ve all heard this advice at least once in our lives. This is horrible advice. The idea behind it is not to waste your life on boring, mundane things, but to “live” life to the fullest. This idea does have some value, but the notion that you should live each day like you’re going to die tomorrow is unsustainable.

Let’s entertain this philosophy for a minute: okay, this is the last day on Earth. Well, I’m certainly not going to work or school. I’m not going to do anything healthy for myself or others, and I won’t be making any investments for my future.

If today were the last day on Earth, I would blow through my savings, liquidate all of my assets and investments, and generally ruin life for Future Brian.

The point is this: if you lived even one day like it’s your last, it would take decades to recover from the damage it would do—if that’s even possible. I’m even being conservative and keeping it mild.

If everyone lived each day like it was their last, the earth would be filled with chaos: rape, murder, fights, theft, and all manner of debauchery.

Why bother entertaining advice or idioms that, if implemented, would ruin your life—or all of humanity if followed on a mass scale?

Now, let’s extract the valuable lesson embedded in this idiotic saying and apply it into something actionable and healthy. I’ve contrived an epithet for this philosophy: 

Retrospective Regret.

(I am not claiming to have thought up this idea; I’ve probably never had a unique thought in my life, but I am going to put this philosophy into words, followed by actionability).

You’ve probably heard stories of an elderly or terminally ill person lying on their deathbed. They’re asked, “do you have any regrets?” or, “what do you wish you could do more [now that it’s too late]?”

Typically, the answer is something like “I wish I could have spent more time with my family; I wish I could have hugged my son one last time; I wish I had spent less time at the office,” and other regrets that they now have in retrospect.

This is Retrospective Regret. In retrospect, you regret something.

Now let’s leverage this same method of thinking and integrate it into a philosophical framework. If you are capable of projecting into the future and anticipating what you might regret—especially regrets of significant valence—you have tapped into a method that can inform your choices for the rest of your life.

Not everybody has a clear idea of what they would regret if they were to die tomorrow—or even fifty years from now. Think about it very deeply, and be honest with yourself: what have you regretted in the past? What do you regret now? It’s likely that what you will regret in the future will be related to—or at least informed by—your past and present regrets.

For instance, Past Brian regrets spending so much time on RuneScape when he could’ve been honing his craft on the drums. Yes, seventeen-year-old Brian did play a lot of drums, which is great, but he also played way too much RuneScape.

Present Brian still plays too much RuneScape, although now he’s far more aware of his past regret, and should be is careful to keep that at the forefront of his mind.

Logically, I can assume that a hundred-year-old Brian would regret spending so much of his life on RuneScape (or any other game) instead of doing something productive and healthy. I have thought this far into the future and have molded my current habits to reflect more of this thinking—both avoiding unfavorable habits and repeating favorable ones.

Whenever I enter the hypothetical mind of Old Brian, I think: “Would I regret this? Do I really want to spend so much time on this?”

I answer honestly: NO! (Grumble, grumble.)

Okay, fine—I’ll play an hour today (instead of six) and then spend the other five hours reading, writing, learning, and going out of my way to clean, do chores, and spend time with my loved ones.

“Will I regret this?” I ask myself (and Future Brian by extension). No, certainly not. Oddly enough, although it sounds appealing to spend six hours in front of a screen (okay, maybe not when I put it that way), I feel way better—both physically and mentally—when I spend my time productively. Future Brian will thank me.

Another useful method is one related by James Clear in Atomic Habits in which he describes things in terms of identity rather than action. It’s totally understandable if you’re incapable of divining what you may or may not regret in the future; that level of foresight isn’t universal. Instead, frame it this way: “What kind of person do I want to be? Do I want to be generous? Do I want to be strong? Do I want to be wise?”
If you want to be generous, start sacrificing your time and money to those who have less than you. If you want to be strong, you better get yourself into the gym. If you want to be wise, keep reading Brian’s Blog start devoting time to reading and studying. Consider your actions with this thought in mind: “What kind of person do I want to be?”

This is the practical application of Retrospective Regret. If I’m honest with myself—and I always try to be—I know what I will and won’t regret in the future. I use this general metric to inform how I choose to spend my time and how I direct my choices.

People often articulate regretting not spending enough time with their family; I would regret that as well. I have now made it a practice to tell my mother I love her and to hug her every day. Before I implemented this practice—one born from my philosophy of Retrospective Regret—I still showed affection for my mother. I hugged her and told her I loved her, but not every day. She appreciates it, and Future Brian will too.