I remember four years ago, I was asked to fill in at the very last minute to host at an event full of cosmetics CEOs (Leeza Gibbons had cancelled). One powerful guest — a woman high up in the world of “beauty” — was surprised to see me. She hadn’t heard about the last-minute changes.

“Ah well,” she shrugged, “you’ll do fine for us as a fill-in, because you are what we call ‘somewhat aspirational.'”

That’s stuck with me for a long time.

Somewhat aspirational. I loved it. Didn’t know what it meant. But I found it to be hilarious and cuttingly honest, which I admire. I considered getting a T-shirt with the words typed out across my chest. I wondered at the time what it was that made me “somewhat aspirational.”

Maybe it was that I had written a great deal about the challenges professional women face, both at home and at work — and revealed my own failures along the way (including a sleep-deprived tumble down a flight of stairs that left my 4-month-old in a cast) — perhaps that made me more approachable.

Or could it be simply that I was at the end of a 16-hour day and had swooped in to bail out Leeza. Maybe my vulnerability was raw and apparent. Maybe it was that. Since then, I have dug deeper and defined the label myself.

I was only “somewhat aspirational” because, while I had accomplished so much, I had yet to begin to crack the code on the Third Metric. I’m talking about questions many women are left with when they achieve financial security, gain power or success — or all three at once. Here are the questions. Think about them for yourself:

What about me?
When do I sleep?
Am I happy?
Am I mentally healthy?
Am I physically healthy?
Am I giving back?
Am I remembering where I came from?
What about my friendships?

My answers to those questions were “maybe” or “no” or “I DON’T HAVE TIME TO THINK ABOUT IT!” I now more than “somewhat” aspire to figure out the Third Metric. I have to. I have two daughters, and I truly believe we can do better.

Arianna Huffington and I have set out to find it, with the help of some incredible women, and a few good men, too.

A few years ago, I noticed Arianna on the set of Morning Joe, and she looked especially rested for six in the morning. She told me she had slept seven hours, even though she had to get up at 4 a.m. for the show. How was that possible?

“I make sleep a priority,” she told me. In fact, “I think every woman should sleep her way to the top.” She actually means sleep. And with that, she started to worry about me, offering advice and opportunity.

Arianna is a modern-day, hot, fairy Godmother. She shares her success with other women, expecting nothing in return but the joy of being able to do so. Together as friends, we have addressed sleep deprivation, overmedicating, food issues, marriage, relationships, parenting, exhaustion, and every other challenge that successful, but overstressed working women face every day. We came up with the idea for the conference at a hastily put together breakfast in Washington, D.C., during the inauguration, after weeks of having to reschedule in our home base of New York City.

We were having a tough, deeply personal conversation about life, relationships and our many work projects. Arianna confronted me about my ability to take care of myself while balancing so many different challenges and opportunities. I had few answers, if any. Mostly, I stuttered and hemmed and hawed — a sign that trouble was on the horizon for me if I didn’t learn fast.

So what did we do? We made a plan — a plan based on our friendship and hope to help others — to solve this terrible riddle together. Out of that conversation at breakfast, “Redefining Success, the Third Metric” was born. The goal: to share success with others, but to also share secrets of success, especially secrets behind achieving the Third Metric. I will be moderating panels all day next Thursday and can’t wait to see what we all learn.

Mika Brzezinski is co-host of MSNBC’s Morning Joe, a columnist for Cosmopolitan and a three-time best-selling author, most recently of Obsessed: America’s Food Addiction — and My Own.

This post is part of a series produced by The Huffington Post in conjunction with our women’s conference, “The Third Metric: Redefining Success Beyond Money & Power” which will take place in New York on June 6, 2013. To read all of the posts in the series and learn more about the conference, click here.

This story appears in the Issue 51 of our weekly iPad magazine, Huffington, in the iTunes App store, available Friday, May 31.