Those who are not shocked when they first come across quantum theory cannot possibly have understood it.
"The Philosophical Writings of Niels Bohr, Volume IV: Causality and Complementarity" edited by Jan Faye and Henry J. Folse (1998); later quoted in Karen Michelle Barad "Meeting the Universe Halfway: Quantum Physics and the Entanglement of Matter and Meaning" (p. 254), 2007.
