Nothing really matters

Mattresses

“No one really knows what mattresses are meant to gain from life. They are large, friendly, pocket-sprung creatures that live quiet, private lives in the marshes of Sqornshellous Zeta. Many of them get caught, slaughtered, dried out, shipped out and slept on. None of them seems to mind this and all of them are called Zem.

Mattresses make a variety of noises that are not supposed to be able to be made by other lifeforms throughout the galaxy, such as willomies, gobbers, flurs, and glurries. Those being only a few examples.

Mattresses are also capable of doing things floopily, meaning in a floopy manner. “

See: http://hitchhikers.wikia.com/wiki/Mattresses