If people do not achieve their goals and dreams, they might be unhappy or unsatisfied for the rest of their lives. For example, a person who dreams of becoming a doctor, but never gets to medical school, she would probably be very disappointed. The same thing applies for any goals a person has in their life. For this reason, it is important that people choose realistic goals that can be achieved.
Some people in this world however, refuses to accept the idea that they cannot achieve ant dreams they have. A person like this may decide to be a doctor even when their teacher says that her grade are not good enough to pass. A person like this will study very hard and would also study to intensely that she will do whatever she needs to do to achieve good grades. People like this are sometimes the people who changes the world around them, Instead of letting the world tell them what they can and cannot do. These people pursue their dreams and try to make the world fit their dreams. So by doing this they can make their own reality.
People who refuse to accept a limit to their dreams can have the power to change the world. Many famous inventors in history did not listen to people around them who said "give it up" or "it won't work". The famous Wrights Brothers were one of the many to deny these people and follow their