At exactly this time last year, I found my new, new thing—gut cleanses! For three whole weeks, I drank the chemically, chocolate paste-like protein shakes. I took two rounds of the horse pill-sized supplements and probiotics daily. I ate from a highly restricted list of anti-inflammatory foods devoid of sugar, simple carbs, soy, corn—even alcohol! And I was totally into it! I mean, how did I not know about this absolute miracle of healthy behavior?! I immediately roped my husband into doing it with me at the beginning of every quarter—21 days of detox from inflammation.

But it was pricey—and I didn’t want to pay for the brand name when I could assemble a similar regimen out of the Whole Foods supplements aisle. So, I iterated—which in the design world means to tweak your approach through versioning. Instead of ordering a 21-day program of shakes and supplements for $500, I bought a $60 jug of protein shake mix, $50 of probiotics, and $70 of supplements. Total savings = $320. Yea, me! With my version 1.0 in place, I pushed through the next 21 days, my motivation doing a fist pump the whole time. Sure, I had to say no to everything at social events, bring my own food on airplanes, go without caffeine in the mornings—but I was clean and proud.

Then, the cheating started.

At first, I would look the other way if the chicken I had ordered was cooked in a little tomato sauce (not a clean food). Then, if I didn’t have access to clean foods I would eat one “dirty” food just to have something to eat so I wouldn’t panic from deprivation. I finished that 21-day cleanse. The next one rolled around. By that time, I could no longer choke down the chocolate shakes without making a face, forgot to take my supplements every other day, and developed disinterest in the foods I could eat. Fortunately, I knew these signs—my cleanse design was not working anymore. I needed to iterate!

I have tracked and researched human behavior change for decades. As a medical student, I started a program for repeat, violent youth offenders that reduced recidivism from 87% to 25%. As a healthcare executive, I designed interventions that showed statistically significant reductions in health risks and improved outcomes. As a CEO/founder of a behavior neuroscience design firm, I have researched thousands of behavior patterns between people who get worse and fail versus those who get better and succeed. And here’s the pith: there are only two outcomes—iteration or failure. Iteration is the anti-failure—it’s the MacGyver factor of experimenting, reconfiguring, and tweaking your way out of any mess. Failure is the exact opposite—it’s giving up and settling for your busted version 1.0—and then blaming yourself for being a bad designer.

In Silicon Valley where I teach, there is a fail fast mentality in the tech industry. This mantra serves as a sort of failure vaccine for designers and engineers who went to Stanford, MIT, or other schools who only accept high-performing, failure-free kids. Normalizing failure allows them to move right into iteration without getting hung up on the emotional self-flogging they would otherwise indulge. In fact, there is a part of the brain, the habenula, responsible for counting failure. And if the habenula registers a failure, it shuts down motivation to try again. Failing fast and iterating frees technology professionals to side-step the habenula so they can keep going.

Legendary designer Steve Jobs was recently characterized as a master “tweaker”—suggesting that his real standout talent was that of iteration, even more so than design. Not only is this evident in the products that he oversaw in making Apple the most successful company in human history, but he applied iteration to his own career whenever he was fired or by creating a new company like Pixar. Steve Jobs, like most famous people, failed numerous times. And it was not that he got back up and kept trying the same thing over and over, expecting different results. It was that he iterated over and over—tweaking his approach each time as he versioned on the solution.

We see evidence of the power of iteration everywhere we look. Jack Ma, the richest man in China, was rejected from 30 jobs, including KFC. Oprah was told she was not right for television. Stephen Curry moved his pivot from his weak ankles to his hips and became the best player in the NBA. Trump unsuccessfully ran for president but now has a highly iterative campaign that is mutating so fast he is, so far, not facing the criticism against him. Taylor Swift started out as a country singer and has iterated her way to winning a Grammy for Pop Album of the Year.

For us not-so-famous folks, iteration holds just as much promise for our success. In my research, patients who control their diabetes always use iteration. As do caregivers of seniors who have higher quality of life. As do spouses of people who recover more quickly from surgery or hospitalization. Mothers who iterate have healthier, happier children. Professionals who iterate have more fulfilling careers.

And me… well, I iterated on my gut cleanse and keep going, with my current version 2.0 being to cleanse the first week of each month.