I define a side as left or right based on the way I am oriented when lying on my back on the bed, head propped on a pillow gandering up at the glow-in-the-dark stars on the ceiling. Thus, for me, the right side (my side of choice when sleeping) is side A (as pictured in the photo below).
However, an opposing viewpoint was brought to my attention. This school of thought said that the left and right sides of the bed are determined by your perception when you walk into the room and are facing the bed with the headboard (if you are so classy as to have one) farthest away from your vantage point. In this case, side B is considered the right side.
I have a theory that more “right-minded” people will think one way and the more “left-brained” people another. Sociological experiment volunteers, anyone? What camp do you represent?
In the meantime, when my boy is staying over, I make it my mission to squirm to his chosen territory and attempt to push him off the bed under the guise of cuddling. Not because I want his “left” side, but more because I like to demonstrate my authority over my box spring mattress set. I sleep in a little corner when I’m alone–all curled up on the upper right side.
NB: The term “right” is used in this discussion as the counterpart of “left” not in terms of “correct” or “just.”