* Vacuum cleaners. The first thing he usually asks a stranger is whether or not they have a vacuum cleaner. If the answer is yes, which it most likely is, he will ask if there is a light on it. I'm surprised how many don't these days. I bought him his very own toy vacuum cleaner (with a light on it) and let him use mine from time to time.
* Lights. Especially lights on vehicles, my camera, and, of course, vacuum cleaners. He likes flashing lights, especially on emergency vehicles. Our neighbor is a policeman, and he stops occasionally in front of the house to turn on the red and blues for Erik. Many people who visit have learned Erik watches them back out of the driveway when they leave and will turn on their hazards or flash their headlights for him. His daycare provider even reminded me to do it the other day when I dropped him off, as Brian apparently does this as well when he takes Erik on a regular basis.
* Wheels. This used to be number one. He will still stim from time to time by spinning the wheels on toys, but not nearly as often as he used to. He inspects the wheels and tires of vehicles in parking lots and likes to say "lug nuts," which always makes me laugh for some reason.
* Fire alarms. I am unsure how he knows what a fire alarm is, but he does. He locates them in each new building we visit and points them out to me and anybody else who passes by. He seems to want reassurance from me that they will not make noise.
* Whether or not our vehicles will start. Yes, he is STILL obsessed with this. A friend of mine was helping me put him in the car the other day and was surprised when Erik freaked out as my key entered the ignition. He also closely watches the dome lights in my vehicle. They apparently flash on and off briefly when I start the engine, which is apparently an indicator of whether or not my Jeep has enough juice to run. He wakes up sometimes talking about my Jeep and if it will start.
* Sirens. This is also making its way down the list. While a siren used to send him into hysterics, making fire season hell on earth in our house on the edge of town, he usually only obesesses about whether a siren might sound when he is very tired or half asleep. He still wakes up from time to time speaking about sirens. I'll never forget the afternoon lightning was striking everywhere and all I could do is blast his stereo and hold him while he sobbed. Thankfully, that usually isn't the case anymore. Sometimes he even enjoys a siren that is far enough away that it doesn't hurt his ears.
There are other things he enjoys but that do not qualify as obsessions. Normal things like going outside, eating a nice, steaming bowl of Malt O Meal, holding Stinky-Dog, or visiting his grandparents. His obsession with tweaking doorstops has finally faded into history. He will occasionally tweak one on his way by, but this doesn't make the list anymore (Note to Self: Locate and replace missing doorstops).
I would bet that a lot of your children have had these same obsessions, diagnosis of WS or not. I find this fascinating. I wonder what Erik would have done before the invention of the wheel. I can just see him wearing a brontosaurus skin diaper, rolling the roundest river rocks he could find around over the ground in a stimmy trance.