Ive used the analogy of water, and wind but never thought about sand. Thats nice.
I was driving down the road and had my hand out of the car. I noticed that with certain movements, my hand would jerk away or I had to fight the energy created by airflow. I started to move my hand in certain directions, and I thought about certain techniques.
I thougt mostly about Iriminage. Thinking about acting like a strong breeze in the wind that swoops around your partner, and then accidentally turns them the wrong way to smash into them..
I dont know, weird thoughts I had I guess. Hopefully Im on the subject
But thanks for the sand analogy, I love that one too.