His own personal quota was one minor invention every 10 days and a major invention every six months. Bach wrote a cantata every week, even when he was sick or exhausted. Mozart produced more than six hundred pieces of music. Einstein is best known for his paper on relativity, but he published 248 other papers. Out of their massive quantity of work came quality.
Geniuses make novel combinations.
Dean Keith Simonton, in his 1989 book Scientific Genius suggests that geniuses are geniuses because they form more novel combinations than the merely talented. This is a clear early intuition about the utility of permitting ideas and thoughts to randomly combine with each other and the utility of selecting from the many the few to retain. Like the highly playful child with a pailful of Legos, geniuses constantly combine and recombine ideas, images, and thoughts into different combinations in their conscious and subconscious minds. Einstein did not invent the concepts of energy, mass, or speed of light. Rather, by combining these concepts in a novel way, he was able to look at the same world as everyone else and see something different.