Happy New Year! Personally, I like these round numbered years. They make me feel optimistic for no apparent reason.

What about you? What’s your frame of mind as you start 2012?

As you probably know, optimism—even when unwarranted–turns out to be one of the most valuable of all leadership traits.

In The Leadership Advantage, an essay from the Drucker Foundation’s Leader to Leader Guide, Warren Bennis tells us that optimism is one of the key things people need from their leaders in order to achieve positive results. Every “exemplary leader that I have met,” writes Bennis, “has what seems to be an unwarranted degree of optimism – and that helps generate the energy and commitment necessary to achieve results.”

In less elegant language, I told my grandson Michael something similar recently when he interviewed me for his college essay.

He asked me, “Grandmother, what factors do you think most contributed to your success in spite of the challenges you faced as a teenage mother without a college education when you started out in your career?”

I blurted out without any forethought, “I was either dumb enough or lucky enough to say ‘Yes’ to almost every opportunity.”

It took a question from an 18-year-old to make me realize that the power of optimism, in the form of saying, “Yes” to job offers I hadn’t sought and challenges I hadn’t imagined I was capable of meeting had profoundly influenced my career path.

Not to mention my penchant for seeing the possibility of a pony when others saw only a little pile of you-know-what in their path.

But I wasn’t consciously aware of this characteristic as power, and that I had it and had used it to positive effect, until Michael asked his question. And the moment I realized that, it hit me squarely in the face that this year, I would own and acknowledge my power of “Yes.”

That’s my personal New Year Revolution.

Yes, I said, “revolution” not “resolution.”

It’s a sea change for me to assert that my own agency–being optimistic and taking the risk to say “Yes” rather than pure dumb luck as I usually tell the story–has fueled my success. Even though I exhort other women to do just that—and how to do it.

It’s much easier for many women to take responsibility for their failures and mistakes than for their successes. We’ve been socialized that way for millennia. So it’s quite revolutionary for us to shift our thinking and start from where the men always have, with the assumption that the world is their oyster and they have every right to own and even brag about their capabilities rather than downplaying them.

The power of “Yes” is the power of affirmation. It starts with an optimistic point of view.

Especially now, when we’ve had a couple of very tough years as a nation, economically, it’s not always easy to follow Monty Python’s admonition to “Always look on the bright side of life.” The ability to believe in yourself and to be optimistic about your ability to solve problems, achieve goals, make things happen as a leader even if you start from a big messy negative place is an essential step toward making those things happen.

What power do you have that you haven’t yet acknowledged?

What’s your New Year Revolution?

This post was originally published in BlogHer Career. Check it and all my every-other-week leadership Q and A columns out there. Got an example to share? Got a question you’d like me to address in a future column? Please comment here or e-mail me.