So for a long long time, like years, I found it strange that though my right upper arm and forearm is stronger than my left, they were smaller than the left. They don't look any smaller, but when I grab my own arms with the opposite hand the right arm absolutely feels smaller in diameter than the left.
A few days ago something dawned on me and I took a good look at my hands. It wasn't that my right arm was thinner than my left, it was that my left hand was bigger than my right. So of course when I grab my right arm with my left hand, the arm is going to feel smaller than when I grab my left arm with my right hand.
I've known that my left foot is a half size bigger than my right foot, but it never occurred to me that would be true of my hands as well.