In essence, Jeffers says that fear is a state of mind and something that can be overcome. It's easy to do things you enjoy, but sometimes it's good to push yourself to step out of the box and try a new experience. You feel the fear, so why not do it anyway and see what happens?
A young child will do the most extraordinary things without a second thought. They haven't learnt how to be frightened and it's only as they grow older and are influenced by the negative reactions of elders around them that they may hesitate in their actions. Parents naturally want to protect their children, but can end up stifling them; that's a fine line that's easy to cross. A healthy attitude is to encourage a child's development and help them explore the huge world that surrounds them. Then, as they mature and the child becomes an adult, they can prepare for a full and active future.
I don't know whether it's because of parental influence, but I'll admit that I'm not a prime candidate for doing 'scary' things and certainly not a person to be too adventurous. However, there are now times when I think twice, remember Susan Jeffers' words and act upon them. The feeling of achieving the unexpected is exhilarating, but there are occasions when I won't do something that I really loathe the thought of. As an example, I don't like heights, so try to stay away from situations that would frighten me. I even find it difficult to watch someone else on a high ledge, or where there's a potential vertically drop. Show me a bungee rope and I'll run a mile.
So why am I advocating that people do things that they fear? Well, it's possibly a case of do what I say, not what I do. I know I'd feel great if I could jump off a bridge, but I choose not to do so and I’ll admit I'm not reaching my full potential. Could you do better? I bet you could. I dare you!