Sometimes my head gets so heavy I can't keep it up. It slowly sinks to the desktop as small muscles strain mightily all the way down my back. It's like a boulder; I can't lift it. I'm trapped. It's an anchor, a ball and chain. I can panic or not. Doesn't matter to the boulder. I can't think of a solution--my brain is rock. I can only struggle helplessly, push against it with my little rubber-band limbs. Only when I give up does it return to normal. I know this sounds like a dream, but it really happens, several times a day.
By the way, when I wrote that I marvelled at what my hand was doing in my last post, I was referring to drawing, not...the other thing.