A little boy seeing an automobile coming along the road sometimes has an impulse to run across the road in front of the automobile, for the fun and excitement of it. If you are a boy and feel like it, why shouldn't you? You have never tripped and fallen in front of an automobile--you have never misjudged the speed of it and been struck and killed that way. You have never seen any other boy killed that way. There is nothing in your own experience to deter you. If the automobile happens to hit you, you will have acquired experience that might be useful to you, but the cost is too great. If you are not dead, you may be crippled for life. If you are convalescing from typhoid fever, you are likely to have a ravenous appetite. You feel very well and you derive considerable pleasure from the milk-toast and soft-boiled eggs you have been getting, but they do not begin to satisfy you. Every instinct within you calls for a big piece of juicy beef-steak and fried potatoes. There is no reason in your experience why you should not gratify your desire--you may have been told by the doctor that it isn't time for that yet and you must be content with what is ordered for you. But if you believe in doing what you feel like and the doctor is out of the way, why not have your beef-steak? I happen to know of two separate cases where this occurred--friends of mine. The doctor in each case apparently took too much for granted and failed to impress upon their minds forcibly enough the need of obeying his orders rather than their own inclinations. The experience came too late--because it brought death with it. Or suppose you are in some out-of-the-way place and are hot and tired and very thirsty and the only water available comes from a supply which is not fit to drink? You may have been told this by some one who knows more about it than you do, but if you believe in ignoring other people's opinions and thinking only of yourself--and the water is cool and clear and you feel like drinking it, why shouldn't you? Suppose it turns out that clear, cool water may be polluted with cholera, or yellow fever, or other deadly germs? You may never recover from the effects of it. These are crude, haphazard illustrations of a principle which is constantly at work in human lives in a great variety of ways. The obvious meaning of it is that your experience, or your own lack of experience, in many questions and emergencies may not be enough for you to go by, or depend upon. Most young people have had very little experience of many things that are liable to have a vital bearing on their own lives, their own selves, their own hope of happiness.