Walking can be a meditation, a practice of just walking. But thoughts bubble up when walking, and if we try to hold onto those thoughts “for later,” we may find we’re not doing a good job of either walking or holding onto thoughts. Jotting down a note can allow us to let a thought go, comfortable we can revisit it later if we choose. We can return to open, non-fixatedness, back to just walking.
Sitting down and writing is different, because writing is a mode of thinking. The additional time it takes—for most of us—to put words down in sequence is a slowing down, reflecting process, and we find that our drafted and redrafted words think with us. We are treated to an expansion of our own mind: a simple, complex adaptive system with our mind influencing the words we put down and the words we put down influencing our mind.
So versatile! Writing to let go of thinking, and writing as thinking.