elevator mystery

Well we moved to our new building in foster city a few months back and my office is on 6th floor. Like any other normal lazy guy I take elevator couple of times a day, and I think out of 4 elevators, one works the hardest, u press the button and 7 out of 10 times this elevator which is second one to the right would reach to u, ready to serve you, I wish there was a way for me to reward this elevator and set it as an example for other 3 lazy elevators to learn.
Another thing i noticed, while I am waiting for the elevator to come up, more often than not the one behind me shows up, believe me, its never the one in front of me, and probably not the one to my right or left.. its always the one behind me.. no matter which one am I looking at. am so bedazzled by this mystery that i thought of writing it up.. I have a medical checkup due later this month, will let you know if its me ;)