He [John von Neumann] had the ...

He [John von Neumann] had the invaluable faculty of being able to take the most difficult problem and separate it into its components, whereupon everything looked brlliantly simple.
 Stanislaw Ulam

Quotes from the same author

As a mathematician, von Neumann was quick, brilliant, efficient, and enormously broad in scientific interests beyond mathematics itself. He knew his technical abilities; his virtuosity in following complicated reasoning and his insights were supreme; yet he lacked absolute self confidence.
 Stanislaw Ulam
There may be such a thing as habitual luck. People who are said to be lucky at cards probably have certain hidden talents for those games in which skill plays a role. It is like hidden parameters in physics, this ability that does not surface and that I like to call "habitual luck".
 Stanislaw Ulam
Knowing what is big and what is small is more important than being able to solve partial differential equations.
 Stanislaw Ulam
In its evolution from a more primitive nervous system, the brain, as an organ with ten or more billion neurons and many more connections between them must have changed and grown as a result of many accidents.
 Stanislaw Ulam
I am always amazed how much a certain facility with a special and apparently narrow technique can accomplish.
 Stanislaw Ulam