A rabbi gave a speech at a bat mitzvah that Kelly attended. He said that being an adult is keeping one thing in each pocket at all times. In one pocket, you keep the recognition that you are a unique, never-to-be-repeated-in-all-the-Universe miracle. In the other pocket, you keep the knowledge that you are small, meaningless and insignificant speck among billions. The secret of adulthood is knowing which pocket to reach into situation by situation.
The formula for adulthood, for humility, for honoring the potential of our own one wild and precious life while recognizing that the 7 billion people around us are trying to do exactly the same thing.
A few more: