Hillary Clinton says this is the most important personality trait a person can have

Hillary Clinton believes that resilience - the capacity to adapt to change with confidence - is the most important personality trait a person can have.

"My mother had a painful childhood," the Democratic presidential candidate wrote on Quora this week. "Her parents abandoned her and sent her off to live with relatives who didn't want her. She was on her own by 14, working as a housekeeper. Growing up, I didn't know any of that - I just knew she was a great mom who worked hard to give my brothers and me opportunities she never had."

Considering the lengthy Benghazi hearings, questions about conflicts of interest surrounding the Clinton Foundation, and an email scandal that won't go away, Clinton has faced her own struggles during her campaign. Thankfully, her mother's journey has served as a lesson in resilience.

"She taught me that life isn't about what happens to you, it's about what you do with what happens to you. No matter how many times you get knocked down, you have to get back up and keep fighting for what you believe," Clinton wrote.

She also pointed to Facebook COO Sheryl Sandberg's recent UC Berkeley commencement speech as a "fantastic" explainer on the topic.

During her speech, Sandberg outlined the three Ps that largely determine our ability to deal with setbacks:

• Personalization: whether you believe an event is your fault
• Pervasiveness: whether you believe an event will affect all areas of your life
• Permanence: how long you think the negative feelings will last

She spoke on how understanding them is helping her cope with the loss of her husband, Dave Goldberg, just over a year ago.

"This is the lesson that not everything that happens to us happens because of us," Sandberg said about personalization. It took understanding this for Sandberg to accept that she couldn't have prevented her husband's death. "His doctors had not identified his coronary artery disease. I was an economics major; how could I have?"