I exist as a platform for cats. Nobody cares whether I can type, click the buttons on my laptop, turn the pages of my book, or even lift the cup of coffee I'm holding to my lips. I am a platform for sleeping or grooming cats. When I get into the damn bathtub and slide myself deep into the scented water, the kitten climbs across my head, curls up on my damp chest, and falls asleep, leaving me afraid to move lest she get dunked and wake up claws-first. And no, I did not make that up. She's done it twice now.
I also exist to be chewed on, apparently.
PS: Husband says that the best word for me is "sap".