(source) 
Stanislaw M. Ulam
(13 Apr 1909  13 May 1984)

Science Quotes by Stanislaw M. Ulam (5 quotes)
I found out that the main ability to have was a visual, and also an almost tactile, way to imagine the physical situations, rather than a merely logical picture of the problems. … Very soon I discovered that if one gets a feeling for no more than a dozen … radiation and nuclear constants, one can imagine the subatomic world almost tangibly, and manipulate the picture dimensionally and qualitatively, before calculating more precise relationships.
— Stanislaw M. Ulam
In many cases, mathematics is an escape from reality.
— Stanislaw M. Ulam
In many cases, mathematics is an escape from reality. The mathematician finds his own monastic niche and happiness in pursuits that are disconnected from external affairs. Some practice it as if using a drug. Chess sometimes plays a similar role. In their unhappiness over the events of this world, some immerse themselves in a kind of selfsufficiency in mathematics. (Some have engaged in it for this reason alone.)
— Stanislaw M. Ulam
In the summer of 1937, … I told Banach about an expression Johnny [von Neumann] had once used in conversation with me in Princeton before stating some nonJewish mathematician’s result, “Die Goim haben den folgendenSatzbewiesen” (The goys have proved the following theorem). Banach, who was pure goy, thought it was one of the funniest sayings he had ever heard. He was enchanted by its implication that if the goys could do it, Johnny and I ought to be able to do it better. Johnny did not invent this joke, but he liked it and we started using it.
— Stanislaw M. Ulam
It is still an unending source of surprise for me to see how a few scribbles on a blackboard or on a sheet of paper could change the course of human affairs.
— Stanislaw M. Ulam
Quotes by others about Stanislaw M. Ulam (2)
When questioned by Stanislaw Ulam, “Which is more important, ideas or things?” Alfred North Whitehead instantly replied, “Ideas about things.”
Mathematics, a creation of the mind, so accurately fits the outside world. … [There is a] fantastic amount of uniformity in the universe. The formulas of physics are compressed descriptions of nature's weird repetitions. The accuracy of those formulas, coupled with nature’s tireless ability to keep doing everything the same way, gives them their incredible power.
See also:
 13 Apr  short biography, births, deaths and events on date of Ulam's birth.
 Adventures of a Mathematician, by Stanislaw M. Ulam, William G. Mathews (Designer).  book suggestion.