Three things I heard at the beginning of my speaking career were business-changing because I took them to heart and acted upon them.
It was eleven years ago when my husband introduced me to the internet. It was business changing - because here was the golden opportunity for anyone to compete with the largest of corporations with very little investment required.
Second, while working with a financial services broking firm, I always heard the Managing Director tell the team "Activity equals success. Activity equals success". I took that to heart. Don't just wait for people to metaphorically knock on your door.
The third was a statement by marketing speaker Winston Marsh when he came to speak with that group.
Winston said "Be a better marketer of what you do than a doer of what you do."