FAIRCHILD AIR FORCE BASE, Wash. -- As a child growing up in New York City, I didn't have much, but I did have a pet lobster and an early philosophy lesson (okay, it was actually a crayfish, but in my youth I didn't know the difference). Every morning when I woke, the first thing I did was run to the fish tank to see my "lobster."

One morning, a rather appalling sight greeted me--a hollow shell. It looked like the lobster, but it had become transparent, it lacked tentacles, and it was definitely not moving. My father reassured me that he wasn't dead and gone; he had shed his shell and was watching us from behind a rock. But why was he hiding? My father explained, he was vulnerable without his shell, and he hid to seek safety.

I don't remember how old I was when this happened, but I found fault with this explanation: "If the lobster needs to be safe and he's safe inside his shell, then why would he ever leave his shell?" In answering this question, my father sprung my first philosophy lesson on me: "If he never leaves his shell, he never gets any bigger."

Throughout my life, the number of times I've reflected on that lesson is astounding. Safety is essential, but it's not our purpose. We are programmed for growth - it's in our DNA. People from all walks of life face frequent choices between these two imperatives: to leave our "comfort bubbles" and dare something new, or to play it safe? Tragically, many choose to deny themselves life's challenges in order to play it safe and, like Shakespeare's cowards, they "die many times before their deaths."

This is not to suggest we should be anti-safety. Safety is a mindset that serves us well, especially when we "leave our shells," but pursued as an ultimate end, results in nothing. Like the lobster, we ought to think of growth as the given assumption, and safety as a way to manage all the vulnerabilities that go with it. The Air Force term for growth is "professional development." That kind of growth requires us to change jobs, take new assignments, and even live in new countries. In each new environment, we listen more, and we learn fast. We harden our shells with the confidence of new knowledge and at the end of the process we are "bigger" in our minds and safe too - we thrive - we lead. Until the itch to leave our shells begins again.