The younger you are, the more likely you will give your attention to many things. That's good because if you're young you're still getting to know yourself, your strengths and weaknesses. If you focus your thinking on only one thing and your aspirations change, then you've wasted your best mental energy. As you get older and more experienced, the need to focus becomes more critical. The farther and higher you go, the more focused you can be--and need to be.