Yet change is usually stressful, and after a certain age, most people don't like to change. When you are 16, your entire life is change, whether you like it or not. Your body is changing, your mind is changing, your relationships are changing--everything is in flux. You are busy inventing yourself. By the time you are 40, you don't want change. You want stability. But in the twenty-first century, you won't be able to enjoy that luxury. If you try to hold on to some stable identity, some stable job, some stable worldview, you will be left behind, and the world will fly by you. So people will need to be extremely resilient and emotionally balanced to sail through this never-ending storm, and to deal with very high levels of stress. The problem is that it is very hard to teach emotional intelligence and resilience. It is not something you can learn by reading a book or listening to a lecture. The current educational model, devised during the 19th century Industrial Revolution, is bankrupt. But so far we haven't created a viable alternative. So don't trust the adults too much. In the past, it was a safe bet to trust adults, because they knew the world quite well, and the world changed slowly. But the 21st century is going to be different. Whatever the adults have learned about economics, politics, or relationships may be outdated. Similarly, don't trust technology too much. You must make technology serve you, instead of you serving it. If you aren't careful, technology will start dictating your aims and enslaving you to its agenda. So you have no choice but to really get to know yourself better. Know who you are and what you really want from life. This is, of course, the oldest advice in the book: know thyself. But this advice has never been more urgent than in the 21st century. Because now you have competition. Google, Facebook, Amazon, and the government are all relying on big data and machine learning to get to know you better and better. We are not living in the era of hacking computers--we are living in the era of hacking humans. Once the corporations and governments know you better than you know yourself, they could control and manipulate you and you won't even realize it. So if you want to stay in the game, you have to run faster than Google. Good luck!