Everyone knows we must exercise regularly to maintain good health. Indeed, staying physically fit is a big part of our culture. We consider (and rightly so) that healthy people are attractive people. Since most of us want to be attractive,there is no shortage of exercise clubs , training videos, magazines , and books offering to help us stay physically fit. . Unfortunately,however,our culture does not place the same emphasis   on mental fitness. Although we admire and love men and women with strong and healthy-looking bodies, we don't have the same degree of respect or attraction for smart, educated and mentally healthy people. This is a shame, because there are immense rewards for people who have developed the ability to think well. If your mind is well trained and flexible , you will be able to understand a great deal of what happens around you. And if you are also well educated---that is,if you understand basic science, mathematics, music, art, literature, history and so on---you will find it much easier to make good decisions throughout your life. Over the long run, _ leads to a sense of control over your destiny and a much better life than otherwise. People who are poorly educated or who don't think well--- that is,people who are not mentally fit see things differently. Their world is controlled by mysterious, but often malevolent  forces. Such people live within a system they will never master, forced to follow the rules they will never understand. Although it may not be obvious , most people spend their lives being manipulated  by others. They are told what to do , what to think, how to spend their money , and what they should and should not aspire to in life. In my opinion, if you want to live well, you must be able to use your mind wel1. For this reason, I want you to be able to concentrate, solve problem, understand complex ideas, and think clearly and quickly. Such skills will make it easier for you to make informed decisions,understand current events,choose good friends, manage your money well, make wise long-term decisions, and appreciate music , art and literature. The key to developing such skills is to enjoy learning, and to have the ability and motivation to teach yourself. The writer of the passage thinks that those who are not mentally fit   _  .
live a poor and mysterious life can't control over their life often do what others do enjoy being fooled and ruled