TITLE: Barry Simon quote
QUESTION [5 upvotes]: In the back of my mind, I have the strong recollection (though perhaps I am confabulating) that Barry Simon once jokingly wrote something akin to
"Let $H$ be a Hilbert space, taken to be separable (are there any other sort?)..."
Can anybody please confirm this, and offer a reference to where the real quote was written?

REPLY [10 votes]: That's how section 1.1 of "Trace Ideals and Their Applications" begins:

Throughout, all our Hilbert spaces will be complex and separable (are there any
  others?)...