This is a serious topic that has might confused plenty of people throughout their whole lives. Some people describe that personalities feel like a cage traps them forever. I once believed that personalities were predetermined by genes, everyone should completely realize your own personality and choose your career carefully. Something even supported my opinion. At that time, I was a soceer fan liked watching matches. I noticed the shy player Messi who always hid himself in the crowd. He was a talented guy at the green feild, but almost everyone thought that his introverted personality would limit himself to be a leader. However, nothing stopped hime to be a big star and a great leader. As I get old, I slowly understand that everyone can be changed by experiencing many things. If we have overcame enough hardships, nothings lets us feel scared. Personalities are just the excuses to failures.