Most people who were old enough to remember anything at the time remember where they were on Sept. 11, 2001. I was at home packing to fly to a work meeting when my friend Karla walked in my room and told me to turn on the TV. The first tower had just been hit.

Last weekend was the 20th anniversary of that dreadful day and, coincidentally, I was in New York visiting friends. I used to live there but moved to Minnesota before 9/11. We picked that weekend because it was best for everybody. Even though we weren't planning to attend the memorial events happening at ground zero -- after all, we were gathering to have some fun -- the memories of that day followed us around like the small dark clouds in the antidepressant commercials. We were OK, but the possibility of sadness was ever-present.

The people I was hanging out with are true New Yorkers. And while I may have lived there for a time, I am not. On Saturday morning, when we watched the memorial ceremony, stories started to flow. Everyone knew people who perished, including me. But because I was not in Manhattan when it happened, I felt as if I should stay quiet.

What I heard from my NYC friends, and what I overheard on my flight back home from Minnesotans who attended the memorial because they, too, lost loved ones, were stories of forgiveness and resilience. Those two qualities are, I believe, essential to body and soul. Health and happiness.

"I was on the George Washington Bridge," says Lee, my former Brooklyn roommate. "Traffic was completely stopped. I didn't see the first plane hit, but I remember when I heard it on the radio moments later I felt like everybody on that bridge slowly looked to the right -- to the towers -- in unison."

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Lee's husband was working downtown that day. She didn't know of his whereabouts until hours later. When she picked him up at the train station, he exited with a silent crowd of people covered in soot.

"My husband was on a business trip and he died in the South Tower collapse," says the woman in the row behind me on the plane. "But your loved one is one of the real heroes and I thank you."

Even though that woman lost her husband, she was compelled to thank and comfort the passenger next to her who had been in NYC to remember a brother. He was one of the first responders who ran into the inferno to help, but did not make it out.

How do people, in times of such loss and crisis, cope? How do they go on? I think it has to do with resilience.

"My personal definition of resilience is doing well when you shouldn't be doing well," says Dr. Amit Sood, executive director of the Global Center for Resiliency and Wellbeing. "Resilience is the core strength you use to lift the load of life. It is your ability to withstand adversity, bounce back from adversity and grow despite life's downturns."

Sood says there are three parts to becoming resilient: learning how to resist adversity, how to recover from it and how to rise above it. That may sound easy, but it takes work.

"The happiest people don't have better things happening in their lives than other people, they're just focusing more on what is good in their lives," says Sood.

He has two tips for how to become more resilient. One is to pay attention to what's important and to take control of what's important. The second is to adjust your mindset. Take note of how you're thinking about challenges and reframe the situation.

To me, that advice is priceless. And the woman behind me on the plane ride exemplified it. She did not let the loss of her husband derail her entire life through bitterness, anger and grief. Instead, she acknowledged the situation and then focused on the positives that emerged from the piles of ash and dust. Positives in the forms of human compassion and love.

I learned a lot on that meaningful trip.

Vivien Williams is a video content producer for NewsMD and the host of "Health Fusion." She can be reached at vwilliams@newsmd.com.