Fifteen years ago today, I heard the news of the September 11 attacks while speaking to my employees in Ohio about vision and values. My plan for the morning was to finish there and fly to deliver the same message to two of our Manhattan offices. I never made it to New York City that day.

Earlier this year, I visited the 9/11 Memorial. It was impossible not to reflect back on my own experience. I stole/borrowed a rental car that day. An employee who had driven from Indianapolis to hear my presentation had rented a car to do so. I needed to drive back to Los Angeles, since all flights were grounded, but no rental cars could be found. So I escorted him back to Indianapolis and took his car. I called the rental car company somewhere near St. Louis. They were exceptionally understanding.

And their understanding was just the beginning of the realization that this crisis was bringing people all over this country together in a way I had never before experienced. People of all backgrounds were united by a common, tragic experience. In those moments, and as I drove across the country, I was given a gift. I witnessed the best of what America is supposed to stand for.

The memorial lives in the shadow of the new One World Trade Center building. It is awe inspiring to stand at its base. A symbol of hope, it’s lines merge together as if into infinity. It begs us to reach higher.

Every year on this day we are reminded to “never forget.” I agree. I’m just not sure we are all united on what we should remember.

I choose to remember how we came together. In the days following the 9/11 attacks, we were a country united. The divisions that existed then, that still exist, were cast aside. We celebrated our common values and embraced our differences, even as we mourned the loss of innocent lives and the loss of our Nation’s innocence as well.

This diversity that exists in our country, when polarized and exploited for political gain, becomes division. We are played off against each other. We become two Americas. This is a cancer. When that same diversity is embraced and celebrated, it becomes a cure.

Fifteen years ago I witnessed a tragedy that brought out the best in us. It is still there, if we choose to see it. On this day, I will honor the memory of those who lost their lives on that day by choosing to never forget that.