Jean-Pierre Serre Quote
Papers should include more side remarks, open questions, and such. Very often, these are more interesting than the theorems actually proved. Alas, most people are afraid to admit that they don't know the answer to some question, and as a consequence they refrain from mentioning the question, even if it is a very natural one. What a pity! As for myself, I enjoy saying 'I do not know'.
Oeuvres, Collected Papers: 1985-1998 (ed. Springer Verlag, 2000) - ISBN: 9783540656838