You're supposed to rotate your bed mattress 180 degrees every 3 to 6 months. I rotated mine last weekend, and now I'm suffering from a bad back and lack of sleep. What a mistake. I think I'm going to rotate my mattress back to how it was this weekend. This is not the first time this has happened. I don't know why one side of my mattress is so messed up compared to the other. I've even tried sleeping on the other side of the bed, but that hasn't helped. I think I've just created that perfect, comfortable depression in the mattress on one side - and nothing else will do.