I hate people who take the elevator one floor. There are people I exempt from this, obviously, like really old people, anyone with a permanent or temporary disability, people carrying heavy things, people pushing carts or other wheeled objects, and in cases where the stairs are inaccessible or difficult to find. (You may laugh at the last case, but we have one building on campus where the elevators are front and center in the lobby but the stairs are in the wings and every time I try to find them I get lost, even though I have taken them down before. I honestly have no idea how to get to them from the first floor, so if I'm in that building and someone takes the elevator to the 2nd floor, even though that is the nutrition research floor, I don't think badly of them.)
But aside from those situations above, I get so annoyed when I'm trying to get to the 9th floor and someone gets in at 4 and presses the button for 5. I want to scream, "IT IS ONE FLOOR! It really isn't that difficult. Stop being so lazy and go up the stairs! That is why you are fat. Well, your laziness and what you ate for lunch. And I'd guess that you probably even waited longer for the elevator than it would have taken you to walk up the stairs." One time someone held the elevator door for me in my office building, and he said, "What floor?" When I said "9" he said "Oh, good. If you said '2' or '3' I was really going to regret holding the door for you." I wanted to high-five the man. Our secretary (who obviously had nothing to do with my previous post on bad secretaries) takes the elevator down one floor because of her "bad knees." I'm sure it has nothing to do with the 2 packs of cigarettes she smokes a day.