Any suggestion how I can keep my cat off the kitchen counter/sofa/whathaveyou?
Most cats don’t like the feel of crinkled aluminum foil, or something sticky (use double stick tape to make a few lines of resistance), or try using a plastic mat designed for use on carpeting so that your rolling chair will roll, but place it upside down so the nubbins stick up. Another tack is to have several mousetraps set, but upside down so that when the cat jumps up on the counter they all go off (but harmlessly). This will probably scare the cat so much it won’t try that again soon.