Ilya Mechnikov is a Nobel Prize laureate in the field of physiology and medicine in 1908. He managed to develop in our country such sciences as zoology, embryology, immunology, physiology and pathology. Thanks to his discoveries, we began to live better and longer! Previously, 50-year-old people were considered old. And now this age is the prime of life. And this is not the limit. Ilya Mechnikov was sure that people would definitely live to 150 years. And he was looking for the “elixir of immortality.” And during these searches I tried to find answers to other questions of humanity: Why are most people pessimists? And how to turn a pessimist into an optimist - to love yourself and life? How are extraordinary children born? What is the secret of long-livers? How and why does a person age? What do we need to learn from animals to live long? What food to eat to avoid dying prematurely? Why does a person feel loneliness even in a crowd? Why do people walk in their sleep? Why do women want to be independent? And in general, how can a person become happy? You will find answers to all these questions in this book. No wonder Mechnikov was called a child prodigy!