"[At this point the interview adjourned to Professor Feynman's office, where the tape recorder refused to start again. The cord, power switch, 'record' button, all were in order; then Feynman suggested taking the tape cassette out and putting it in again.]
"Feynman: There. See, you just have to know about the world. Physicists know about the world.
"Omni: Take it apart and put it back together?
"Feynman: Right. There's always a little dirt, or infinity, or something."
-- From interview "The Smartest Man in the World," in Omni, 1979, included in the collection The Pleasure of Finding Things Out, edited by Jeffrey Robbins, Perseus Books Group, New York, 1999, pp. 198.