In other words, trying to do and cling to too many things cannibalizes our precious limited resources that might be better spent elsewhere — but we’d never know.

That’s where strategic quitting — and understanding opportunity costs — comes in. Simply put, this is the idea that in order to pursue one option, we must forgo certain others, Mr. Godin said. This means choosing between four hours of “The Office” on Netflix, or working on your masterpiece or studying a new skill.

“That’s really expensive,” Mr. Godin said, “because all these hours you could have spent reading a book, coaching the local handball team, or giving back to the community, you chose to be watching television.” At that point, the monetary cost of Netflix is far surpassed by the opportunity cost it represents, he said.

One of those costs is time, which we tend to falsely believe we’ll magically have more of in the vague future, according to this 2006 study in the Journal of Public Policy & Marketing. But, lest we forget: You have the same 24 hours in a day as Beyoncé. If you spend an hour here and there, you have fewer hours for writing your book or working out in the gym.

Quitting is made even harder to justify to ourselves because of the sunk cost of investing our time, energy and resources into something. Imagine you’ve stood in line for 30 minutes only to learn there’s still another hour to go. You’ve already invested that 30 minutes, so dropping out at this point doesn’t sit right with you. But that’s not rational. A paper in the American Psychological Association pegged it on our overgeneralization of the “don’t waste” rule. That is, we feel like we should put those 30 minutes to “good use.”

But refusing to abandon those investments can be costly. For every moment you double down on something that’s not working out, you are forgoing other potentially valuable opportunities.

“The right way to look at sunk cost is to say, ‘I got a gift from my other self, my old self,’ ” Mr. Godin said. “Once you realize that whatever you’re quitting is a gift from your former self, you don’t have to accept.”