To me, being successful means...
Learning to find joy, love, gratitude, and opportunity no matter what is (or is not) happening in our lives while remaining fully present and compassionate with the reality of our own and others' suffering and the light such darkness can reveal for us to share with others.

My definition of success has changed over time. 
I wanted to do something big with my life - and to me that meant being well-known and doing something high profile (like being an astronaut or a famous author). While I still struggle with that old attachment to having my ego-identity validated by as many people as possible, I've come to find the greatest sense of purpose in my life comes from the individual relationships I form and the opportunity I'm given to make a lasting and meaningful difference in the lives of others.