Bill Gates is now 63. He fully acknowledges he's not the same person he was when he founded Microsoft to put a "computer on every desk and in every home."

To assess his quality of life, Gates asks himself different questions that we should be asking ourselves as we age different from those of our youth.

For the 25-year-old Gates, the only question that mattered was posed to assess his business success at the end of the year:
Is Microsoft software making the personal-computing dream come true?

A new set of questions

1. Did I devote enough time to my family?

2. Did I learn enough new things?

3. Did I develop new friendships and deepen old ones?

Gates readily admits these questions would have been "laughable" to him at 25; at 63, they're that much more meaningful.

Oh, and then there's this question tossed in for good measure, courtesy of Gates's friend and mentor, Warren Buffett:

4. "Do the people you care about love you back?"

This is Buffett's own measure of success, which is about as good a metric as you will find, says Gates.

Assess the quality of your life
At the end of every year, measuring work, income, or business performance is certainly important to gauge our success. But how many of us actually sit down and reflect on the quality of our personal lives?

Taking it a step further--the Bill Gates and Warren Buffett way--it's what we do to help impact other people's lives that should matter most in the quality-of-life metric. And since you and I aren't billionaires, we have to start with our own families, friends, work (if you're in a leadership role), and local communities.

What are we doing to make people's lives better within our sphere of influence?

Buffett knows this principle well. He once told a group of students at Georgia Tech his definition of success:

Basically, when you get to my age, you'll really measure your success in life by how many of the people you want to have love you actually do love you. That's the ultimate test of how you have lived your life. The trouble with love is that you can't buy it. But the only way to get love is to be lovable. The more you give love away, the more you get.

Gates "gives his love away" through his Bill and Melinda Gates Foundation, pledging billions to enhance health care, fight disease, reduce extreme poverty, and, in the U.S., to expand educational opportunities.