I was noticing this last night as I sat with friends watching a DVD of episodes of a show I like and was enjoying. But while others can sit in a straight backed chair for hours and barely move, focus entirely on the show, I am:
Trying different positions in my chair, finally getting a second chair to put my feet up on, and later a pillow
Yawning because it was late and I never get decent sleep
Feeling irritable even though it was a show I liked - because I really needed to go to bed but couldn't just leave the gathering
Passing gas (okay, maybe it was something I ate, but still!)
Blowing my nose (allergies)
Getting up several times to pee (I have overactive bladder but don't want to take those Rx meds for it)
Petting the cat helped some. I'm over 50, was diagnosed ADHD in mid-30s. I just feel like I stand out too much with my weird body and my distractibility and wish I could be as calm and stay put and concentrate in the context of what others are doing.