A moment in the history of Dada
From Dada: Art and Anti-Art by Hans Richter:
One day Schwitters decided he wannted to meet George Grosz.
George Grosz was decidedly surly; the hatred in his pictures often overflowed into his private life.
But Schwitters was not one to be put off. He wanted to meet Grosz, so Mehring took him up to Grosz's flat.
Schwitters rang the bell and Grosz opened the door.
"Good morning, Herr Grosz. My name is Schwitters."
"I am not Grosz," answered the other and slammed the door. There was nothing to be done.
Half way down the stairs, Schwitters stopped suddenly and said, "Just a moment."
Up the stairs he went, and once more rang Grosz's bell.
Grosz, enraged by this continual jangling, opened the door, but before he could say a word, Schwitters said "I am not Schwitters, either."
And went downstairs again. Finis. They never met again.