We tend to think of the great Renaissance artists as a homogenous group, but the truth is that they were like any other randomly selected group of people. They came from rich and poor families alike; they had different personalities, different teachers, different motivations. But they had one thing in common: they all spent thousands of hours inside a deep-practice hothouse, firing and optimizing circuits, correcting errors, competing, and improving skills. They each took part in the greatest work of art anyone can construct: the architecture of their own talent.