"Determination, courage, self-confidence lead to success, but we should always remain humble, modest and unpretentious." - Dalai Lama
There is nothing wrong with working hard for what you want, taking risks, and being proud of what you have accomplished. The thing you need to avoid, however, is letting that pride take you over. Humility, modesty, and respect for others are qualities that you need to keep no matter where you are personally and professionally in life.
Remember that where you are in your life right now, you were once in a lower position. No one was born on the top, and if they were, do they really have the right to be pretentious about the position they didn't have to work for at all?
Be proud of where you are, but never forget where you came from.