I love this short conversation which took place between Neils Bohr and his colleague Harald Høffding
They were discussing the mystery of the twin-slit experiment (Of course there are those who argue that there is nothing at all mysterious about this experiment. In my opinion this proves they have not understood it):
Harald Høffding: “Where can the photon be said to be?”
Neils Bohr: “To be? To be? What does it mean to be?
Mind you, Bohr and Høffding were Danish!