Turn off a radio that's been on since morning and the quiet which arrives seems to come from somewhere. It doesn't. It was there the whole time, underneath, waiting for the noise to stop.
Calm probably works like that, which makes openness the right posture and effort the wrong one. Trying hard to relax is just more noise added to the pile. What can be done is subtraction — one fewer input for twenty minutes, then some patience while whatever was already down there comes back up.