Traditionally, most philosophers taught that to be is to do. Your actions are determined by your innermost nature, bolstered by your experience, and what you have become from that, you continue into the future with your actions. From this innermost being, everything was implied: preferences, morality, potential. Then, suddenly, everything got flipped on its head.
Existentialist philosophers like Sarte and Camus taught that to do is to be. Your inner nature has more to do with the sum of the choices you made. If you act differently, then eventually it leads you to becoming a different person altogether. You can be the change you want to see in the world, and watch it bend slowly. And on the flip side, your entire life is as pointless as Sisyphus, and not even killing yourself will give it meaning. Oh shi-
On the flip side of this, since to do is to be, if you give your life a meaning of your own, it will be more meaningful than if this meaning was imposed upon you from outside. We were free to invent the best of natures for ourselves, because we had no nature. You're free.
Now, there are a lot of people worldwide who don't like the idea of freedom. With freedom comes responsibility. When things go wrong around free people, it's their own fault. A lot of people want to be protected, and damn the cost.
And yet, as a free person, your meaning came from you alone. You'll never have a crisis of faith. And no one can make you feel inferior without your definite consent.