"You're vegan? Again?" Nicky laughed. "Didn't you already try that?"

"Why don't you just eat normally, everything in moderation?" Pam chimed in.

Everyone at the table laughed, partly at me, partly at Pam, who, well into her second mojito, was hardly the poster child for moderation.

I was with my high school friends; the six of us have been meeting for dinner once a month for over 25 years. We don't stand on ceremony.

The conversation didn't last long; no topic ever does at these dinners. But it did get me thinking. Am I a failure because I'm vegan again? Why couldn't I sustain it last time? And if I couldn't, why am I trying again?

One way to look at it is that behavior change is like quitting smoking or alcohol; sometimes it takes several tries to permanently follow through on a commitment.

But there's another perspective that's also true: not everything needs to be sustainable. It all depends on what you want to achieve.

I'm leading a strategy offsite this week with the CEO and leadership team of a technology organization whose revenues exceed $600 million. We've spent several days redesigning parts of the organization: we created a new organizational structure, put people in new leadership roles, and clarified accountabilities. This is an excellent company with capable leadership, a solid strategy for growth, and credible targets to become a billion dollar company in the next three to five years.

Referring to the new organizational structure we had collectively designed, one of the CEO's direct reports spoke up. "This won't work," he said, "At $900 million it will be unwieldy."

The CEO reflected for a moment and then replied, "It doesn't have to work at $900 million. It has to work for now. We'll change it again, probably at $750 million."

Brilliant. Mostly, things are useful for a particular time. Then they're not. For many things, it's better to have a temporary solution that you're willing to change than a solution you think is permanent and, as a result, get stuck on.

Process re-engineering? The one-minute manager? Management by objective? Guerrilla marketing? It's easy to dismiss them all, and so many other ideas, as fads. Here one day, gone the next. Better not to get sucked into them in the first place.

But, instead, consider how each "fad" might have been useful, perhaps in your organization, for a period of time. And that might be just fine. For something to be a great success, it doesn't have to last forever.

The challenge? Not thinking of any solution as a cure-all in the first place.

Because when we think of something as a panacea, we ignore its weaknesses and negative side effects. And then, eventually, when the inevitable flaws are exposed, we lose faith in the solution completely. We discount any value it provided. Because it never lived up to our expectations, it never fully worked.

And then we go off in search of the next magic bullet. Our yearning for the solution, the formula that will solve all our problems, the panacea to our angst, is strong. It's also misguided.

Because nothing is perfect, and nothing lasts forever. So we're better off seeing every solution as temporary, every tool as potentially valuable and probably fleeting. That's true whether the change is personal, like a new diet, or organizational, like a new management tool, a new organizational structure, or a new diversity program.

Seeing every solution as temporary yields surprising dividends:

• It becomes easier to commit to. If we know it's not perfect and not forever, why not give it a whirl?
• It becomes easier (and faster) to implement. If we know the initiative isn't forever, let's not make it perfect; let's just make it work.
• It becomes easier to get others involved. If we acknowledge that a solution is imperfect and unfinished, other people are more likely to participate in improving it, which gives them a sense of ownership.
• It becomes easier to pay for. If we're not going to make it perfect, and it's not going to last forever, let's not invest a huge amount of capital up front.
• It becomes easier to let go when appropriate. If we haven't invested a huge amount of money, or our identities, in the solution, we'll waste far less time and energy evangelizing about how great it is and holding tight even when it no longer adds value. Certainty, when it contradicts the evidence, is never a good thing.

These five side effects of an "it's not forever" mindset drastically increase the chance that you're going to do something instead of just think, talk, plan, and argue about doing something.

We change. Situations change. The people around us change. And the tools we use should change too.

A few guidelines: 

• Distinguish between a commitment to an outcome - like marriage, staying sober, being healthy, having a profitable organization - and a commitment to the tools you use to fulfill/achieve that outcome. The tools can be fleeting while the outcome can be permanent.
• Understand the value you're getting and why. Then decide on the evidence that will indicate it's no longer providing that value. That way you'll know when it's time to move on.
• Decide when you're going to reassess. It doesn't help to constantly second-guess yourself. That makes it impossible to follow through; you'll give up in a moment of weakness only to regret it later. Instead, decide when you're going to reassess, and commit fully until then.

When I decided, a month ago, to cut meat and dairy out of my diet, I was feeling overstuffed. I wanted to feel clean again and going vegan helps me do that. Also, what I know about myself is that, when I'm feeling overwhelmed and out of control, I do things that help me feel back in control. Like cut my hair. Or cut things out of my diet. It's a coping mechanism that helps me feel less overwhelmed in the rest of my life. When I'm feeling back in control, I'll probably change my diet again.

It's also good to remember that just because you don't have to commit forever, doesn't mean everything will be short-lived. "Some things, like my dietary choices, are fleeting," I told my old classmates toward the end of our dinner, "Live with it. You don't have to make the same choices and I'll probably be eating differently next time we meet."

"But don't worry," I added. "Other things, like our dinner tradition, will go on forever."