“Frank Oppenheimer noticed that his brother’s passions were always mercurial. Robert seemed to divide the world into people who were worth his time and those who were not. “For the former group,” Frank said, “it was wonderful. . . . Robert wanted everything and everyone to be special, and his enthusiasms communicated themselves and made these people feel special. . . . Once he had accepted someone as worthy of attention or friendship, he would always be ringing or writing them, doing them small favors, giving them presents. He couldn’t be humdrum. He would even work up those enthusiasms for a brand of cigarettes, even elevating them to something special.”
―
Kai Bird,
American Prometheus