A slipping thought in sleep!!

Yesterday a very funny thing happenned with me. Quite embarrassing if you consider my age. While I was sleeping I suddenly fell off the bed with a big thumping noise. Even as I lay on the floor half-asleep and hurt, I could not help myself from laughing when I heard my sister, who had woken up by the noise, blabbering "ole baby" continously for over two minutes, obviously semi-conscious. As I managed to find my way back to the bed in the darkness, my sister came to me to check whether I was fine. I assured her I was fine and had only fallen from the bed. As she went back to sleep, I had one lingering thought running in my mind: In which way had I hit the floor, as in, on my stomach or on my back because each body part was paining equally bad!