To have a goal and mind, be it a particular mission or type of work that you are interested in doing, and to work hard to attain it. Since your own personal satisfaction of achieving your goals is invaluable.
I hope that one day we are able to land humans on Mars. This would not only increase our understanding of the planet itself. But more importantly provide a huge leap in our understanding of manned spaceflight.
Since I was little playing with plastic blocks and putting together models. Air and Space have always been something I wanted to be a part of.