Why must they always sit in the centre of everything? On the nice pile of paperwork which they then rip to pieces to make a nice nest out of...on your arms as you sit at the computer working, which slowly go dead as you try and move the mouse without disturbing them...on your legs, particularly when they are at an uncomfortable angle so they slowly bend backwards at the knee with the weight of a sleeping cat...on your chest while you are sleeping so that eventually you feel you can't breathe because all the air is being slowly squeezed out of your lungs...or even just walking backwards and forwards in front of your face, rubbing themselves off you and walking across your keyboard while you try and type something...
Nothing is sacred to a cat. That glass of water you just put down is actually a nice drink your prepared specially for them, the bowl of ice-cream will do just nicely while you aren't looking as a pre-dinner snack, and the sofa is the perfect spot for vomiting up a dead mouse on, that fluffy cushion will soak up the bile very well thank you. There is no sense of guilt like there can be with a dog, instead they will sit there watching you as you clean up their poo/puke/headless bird-leavings/all three in the one go with a look of utter disdain on their faces.
The well-known phrase comes to mind - dogs have owners, cats have staff. I regret to say I am, like the majority of cat owners, a complete sucker. I get up to let them in doors, I refuse to get up to let people in doors due to a cat being comfortable on my lap, I put up with their general ill-behaviour, frequently catch the mice they lose in the house, worry about them late at night, chase off other cats while roaring like a lion to stop them scaring my babies, and just generally I am a total sucker, pandering to my cat's whims. But I am not staff. Staff are paid, staff have rights, this is pure slavery.