I have weird ... touching habits
Whenever I'm sat on the computer I constantly scratch the mouse rhythmically. I don't know why. Part of my nail is permanently black as a result, and the mouse is visibly damaged.
Whenever I'm in a garden centre I have to feel all the plants: their leaves, petals. I stand there literally stroking them for the different textures.
Finally, when I'm reading a book, I can barely be still. I make rubbing motions with my index finger and thumb as I read. I don't quite feel as comfortable without doing this.
Also, when I'm sat down, I'm usually either tapping or shaking my leg.