"Apart from my architectural studies and rare visits to the opera for which I had to go hungry I had no other pleasure in life except my books. I read a great deal then, and I thought deeply about what I read.
All my free time after work was devoted exclusively to study.
Thus within a few years, I was able to acquire a stock of knowledge that I find useful even to this day. But even more than that: During those years, a view of life and a definite worldview took shape in my mind. These became the granite foundation of my conduct at that time. Since then, I have extended that foundation only very little, and I have changed nothing in it. On the contrary. I am firmly convinced today that, generally speaking, it is in youth that men lay the essential groundwork of their creative thought, wherever that creative thought exists. I distinguish between the wisdom of age which can only arise from the greater profundity and foresight that are based on the experiences of a long life and the creative genius of youth.
The latter blossoms out in thought and ideas with inexhaustible fertility, without being immediately useful, because of their very exuberance. These ideas furnish the building materials and plans for the future. And it is from them that age takes the stones and constructs the building—unless the so-called wisdom of age smothers the creative genius of youth."
~ Adolf Hitler Mein Kampf Volume 1 Chapter 2.2