I slept without a pillow last night. I know it sounds crazy but I had a theory about why I wake up most days feeling like someone had been hitting me with a baseball bat all night. It has to do with the memory foam pad on top on my mattress. The way I see it in my head is that my shoulders and back are sinking into the mattress enough to put my neck at a weird angle as it tries to reach the pillow. This angle plus the strain on my neck and shoulder muscles from trying to resist this stretch are what have me waking kinked and beaten. From what I can tell, it seems like laying on the bed without a pillow will allow my hips and shoulders to sink in while keeping my spine straight.