People do not wander around and then find themselves at the top of Mount Everest.
Life is a classroom -- only those who are willing to be lifelong learners will move to the head of the class.
money is not everything but it ranks right up there with oxygen
The way you see life will largely determine what you get out of it.
The complaining customer represents a huge opportunity for more business.
Don't give up just because of what someone said. Use it as motivation to push harder.