What is our limit, be it taking pain or seeking for our goal? What does it take to become successful?

Can we feed a horse if he is not thirsty? Does limit mostly manifest of our mind? We have created an artificial wall and scared of getting hurt crossing it?

Watching Hollywood, listening, or reading autobiography it seems one has to do the impossible. It requires sweat, pain, hard work apart from many sacrifices.

Does that mean this limit is more of artificial, we have created it?