It is for me(most of my life)....but since I started wrapping less and sleeping on the opposite side every other night, I've noticed less of a difference. When I do wrap I alternate the direction I wrap in every other night.
The left side of my hair is thinner than the right side. It's been that way all of my life. I've tried sleeping on my right side, but I don't think there is much I can do about it. /images/graemlins/smile.gif
I've never actually noticed this with my hair, but one thing I do notice it I tend to take care of my left side first and a lot more than the right side.