Watching the Chilean miners emerge from their temporary tomb this week, I was struck at how the men and their families have a crystal clear identifier in their lives: "That's Roberto, he's one of the miners." "Look, there's Maria, she's one of the miners' kids." It's one of those rare signature events that they -- and we -- will remember. It is their defining moment.

And for them, it's a data point to determine the before and after. This was my life before the defining moment, and this is my life after, a life that will be deeply influenced by the event itself. Trauma survivors often shift their focuses post-trauma, using lessons learned during the crisis to shape their futures. Even if they continue on their work and life path, they see the world through an altered lens.

It's an interesting thing about defining moments: We so often don't choose them, they choose us. Call it fate, call it God's will, call it luck. Any way you slice it, it's usually something that happens to us -- a job loss, a lottery ticket, a death, illness, or a girl telling you to sell your house to be more generous.

The real test comes with how we respond. Will we choose to step off our comfortable paths and embrace the uncertainty that comes with the new post-event world? Will we allow ourselves to be jolted into focusing on the things that matter? Will we let the defining moment define us for who we were or who we can be?

Defining moments, large and small, happen. The provide us the opportunity to be bold in our thoughts and our actions. The rest is up to us.