Each doctor has an opinion of his own, but a patient can have faith only in one doctor. Otherwise, the patient will dig his own grave. Again, each individual has his own appetite and a special liking for particular foods. But if we pay all attention to food, then we shall get unfortunately unhealthy and frustrating experiences. Zatopek illumines us: "At one time I was so confused by various doctors' good advice that I almost died of hunger and thirst. If you come to think of it, you never see deer, dogs and rabbits worrying about their menus and yet they run much faster than humans."