Before bed last week:
Me, reading "Endurance" about the epic Antarctic Shackleton expedition in 1914-16, to John: "They kill seals! With their bare hands almost! Now they're killing the dogs! Ahh, they haven't changed their underwear in five months! Whoa, they are using ice for toilet paper!"
John, reading "The Universe in a Nutshell" by Stephen Hawking, to no one in particular as he picks up the book with a sigh: "Oh Hawking, you incomprehensible genius."