[During a brainstorming session at Princeton with Niels Bohr, during which Bohr paced around his office, he] then asked me if I could note down a few sentences as they emerged during his pacing. It should be explained that, at such sessions, Bohr never had a full sentence ready. He would often dwell on one word, coax it, implore it, to find the continuation. This could go on for several minutes. At that moment the word was "Einstein." There was Bohr, almost running around the table and repeating: "Einstein…Einstein…" It would have been a curious sight for someone not familiar with him. After a little while he walked to the window, gazed out, repeating every now and then: "Einstein…Einstein…"
At that moment the door opened very softly and Einstein tiptoed in [from the office next door]. He indicated to me with a finger to his lips to be very quiet, an urchin smile on his face. He was to explain a few minutes later the reason for his behavior. Einstein was not allowed by his doctor to buy any tobacco. However, the doctor had not forbidden him to steal tobacco, and this was precisely what he set out to do now. Always on tiptoe he made a beeline for Bohr's tobacco pot, which stood on the table at which I was sitting. Meanwhile Bohr, unaware, was standing at the window, muttering "Einstein…Einstein…" I was at a loss what to do, especially because I had at that moment not the faintest idea what Einstein was up to.
Then Bohr, with a firm "Einstein" turned around. There they were, face to face, as if Bohr had summoned him forth. It is an understatement to say that for a moment Bohr was speechless… A moment later the spell was broken when Einstein explained his mission and soon we were all bursting with laughter.