There are two well-known facts that no human could ever dispute: Cats are jerks and they love knocking anything off counters seemingly to watch your look of sheer panic. But science says otherwise. Cats actually knock things off counters because they toy with their prey – and destroying your beloved [Insert your favourite thing in here, like the good crystal your gran gave you at your wedding], everything gives them a way to practice this behaviour.
Dr. H. Ellen Whiteley explains on her site, "Your cat's instincts tell her that paperweight or knickknack could turn out to be a mouse. Her poking paw would send it scurrying, giving her a good game (and possibly a good lunch)."
They say cats are actually relatively intelligent so, eventually, they will figure out that your wine glass isn't a mouse and stop nudging it off the table. But the humans must hide their panic because Whiteley says "Once a cat learns that knocking something to the floor will bring humans on the double-quick, she may actually do it on purpose to get your attention, particularly if she feels that a meal is long overdue." Basically, it could be saying "give me attention now human" or "feed me now slave".
Just to prove they are in fact intelligent (and possibly here to take humans as their slaves) the videos will amaze you.
Science didn't dispute that cats are jerks, that's a hard fact!