Answer:
I saw a man in white, he looked quite a sight. He was not old, but he stood in the cold. And when he felt the sun, he started to run. Who could he be? Please answer me.
This is in a realm of true and in a realm false, but you experience me as you turn and toss.
Though desert men once called me God, today men call me mad. For I wag my tail when I am angry. And growl when I am glad.
In the night a mountain, in the morning a meadow.
I weaken all men for hours each day. I show you strange visions while you are away. I take you by night, by day take you back. None suffer to have me, but do from my lack.
The more of me you take, the more I appear behind you. What am I?