Von Neumann's ability to instantaneously perform complex operations in his head stunned other mathematicians.[141] Eugene Wigner wrote that, seeing von Neumann's mind at work, "one had the impression of a perfect instrument whose gears were machined to mesh accurately to a thousandth of an inch."[142] Paul Halmos states that "von Neumann's speed was awe-inspiring."[12] Israel Halperin said: "Keeping up with him was ... impossible. The feeling was you were on a tricycle chasing a racing car."[143] Edward Teller wrote that von Neumann effortlessly outdid anybody he ever met,[144] and said "I never could keep up with him".[145] Teller also said "von Neumann would carry on a conversation with my 3-year-old son, and the two of them would talk as equals, and I sometimes wondered if he used the same principle when he talked to the rest of us. Most people avoid thinking if they can, some of us are addicted to thinking, but von Neumann actually enjoyed thinking, maybe even to the exclusion of everything else."[146]

"[...] John von Neumann was probably the most influential mathematician who ever lived," wrote Miklós Rédei in "Selected Letters." James Glimm wrote: "he is regarded as one of the giants of modern mathematics".[152] The mathematician Jean Dieudonné called von Neumann "the last of the great mathematicians",[153] while Peter Lax described him as possessing the "most scintillating intellect of this century".[154]

John had earlier said to his mother, "There is probably a God. Many things are easier to explain if there is than if there isn't."

Interesting. Reddit led me to believe that only simple and naive people believe in God.