My mom always like to joke about how I hate change, but it's true, It's extremely distressing for me to change my established routines, my routines ground me an gives me a sense of order in a world that to me seems terribly chaotic, and chaos causes my anxiety to go through the roof. In the same way if something is not ordered and/or placed the way I am used to having it I go nuts to the point of freaking out and having a meltdown.
I used to work in the kitchen of a local preschool run by the YWCA and when preparing for lunch I put the cups, pitchers, plates, bowls, silverware, and serving bowls with food on serving carts for each room and I had a certain way of setting things up on each cart. if someone else set up a cart and things were not in the "correct" spot I compulsively "corrected" it, to the annoyance and humor of my co-workers and job coaches, (and I humorously retorted to one of the job coaches by jokingly pointing out his own OCD-like tendencies). Same thing when putting dishes away; cups had to be ordered in just a certain way and the red and clear cups could not be mixed up together. When putting washed dishes on a rack to be sent though the sanitizer things had to be placed on the rack just right, to the annoyance of a fellow Aspie co-worker. If I was prevented from doing any of this ordering I would get extremely upset, and even have a meltdown.
People, my mother especially, think I'm crazy because I refuse to move my furniture every once in a while, but I find re-arranging furniture to be horribly distressing. When I was a kid I would come home from school and freak out because the living room or my bedroom had been re-arranged, my mom would never get why I was so appalled and horrified. Sorry, I'm used to things being in a certain place and when it changes it throws me off completely.
Oh, and if you say you will be at my place at 2PM, please be actually at my place at 2PM, not, say 2:30 or 1:30, unless you want me to go into a state of extreme anxiety, or even panic.