If you're of a certain age, you probably remember water beds. Perhaps your parents owned one when you were a kid and you have vague, nausea-inducing memories of being lulled to sleep on a huge mattress full of water. Or maybe you owned a water bed yourself, because, well, at the time you thought it was the coolest thing around.
In a 1986 New York Times article, the water bed is described as "filled with up to 250 gallons of water and who knows how many tons of sexual promise." The Times also cites an advertisement from 1970 that read, "Two things are better on a water bed. One of them is sleeping."