A Question About Elevators

I'm not a terribly impatient person. I have no problem with letting the elevator doors close as they choose to. But I've often wondered why elevator designs include a "Close Door" button that doesn't actually make the door close any faster. Everywhere I've gone, it's the same thing. You push that button and nothing happens! That is, until recently. I've found an elevator at the school library that actually responds to the "Close Door" button. So here's my question, is this door just a fluke or have I just ran into elevators all my life that don't work. What is your experience with elevators and the "Close Door" button. Do they ever work? Have I just been denied this function for most of my life while others have been able to enjoy it? Or have I just found an elevator that somehow missed the day at training where they teach elevators never to close on command?