What I Think of What Author Isaac Asimov stated

What I think he meant on his statement is that no matter what you hear, been told by or having a sense of something by other people that made you not wanting to do it anymore, you still must do it. As long as you know if it's right, and achieving your goals, it doesn't matter about the people around you. Some would just try to discourage you and so you wouldn't succeed on what you're trying to do. They can be jealous, and selfish therefore, you have to listen to your own thoughts.