Sometimes i'll start to do it when i'm stressed... But, usually, i just do it for no particular reason. It depends on what position i'm in and what i'm doing, though. For example, i usually rock back and forth a lot if i'm sitting in a hard chair(where you generally end up sitting upright instead of lazily laying back like in a soft chair or couch). Right now i'm doing it, usually do when i'm at the computer, because the chair here is hard and has me sitting upright. When i'm sitting in my recliner in the living room, or another chair where i'm resting my back on the chair, i almost never rock, however. But, if i'm sitting with my back resting on something, or sometimes when i'm laying down, i'll move my foot. If i'm in a recliner and my feet are up and hanging off the rest part, i'll often "flap" one of my feet. I also bounce my right leg a lot when i'm sitting somewhere(if i'm not rocking). When i'm standing up i don't stim too much, but occasionally i'll shift my weight back and forth from side to side or lean against something and rock side to side. Now and then i shake my hands, too(i don't flap, but just shake them really fast down by my sides), moreso when i get stressed with that one though. And i pick at my skin(the skin under my fingernails is one spot i like) a lot, and have done this since middle school or so. I stim a lot more now than i ever used to as a kid or young teen, though. When i used to do it, it was pretty much limited to things like the bouncy leg... Or maybe just incidental things like repetitively making a noise with a toy for a little while, but not something i always did. Thinking about it, it seems like i must have done some kind of stimmy things back then.. Because i did like to fiddle with things to stimulate my senses... but there weren't any that i kept repeating. For example, I might find that if i do a certain thing with a toy that it makes a satisfying clicky noise and repeat it over and over for awhile, but the next day i probably wouldn't go back to doing that same thing. Plus, whenever i repeated something that bothered my parents by making a noise i would get yelled at, so most noisy habits got stopped quick. They still start complaining if i bounce my leg when i'm in the car with them, because apparently it makes the car move or something. And then i'll stop, but likely start again when i stop thinking about it.