Do not be deceived by their immateriality. Thoughts are things—that is, objects in the mind. This is where the drive to de-clutter originates. Ah, subtraction! Thank you, Marie Kondo. Space is love.
One of Zen’s most archetypal images is that of a monk sweeping. On the outer level, the monk is dealing with sidewalk debris. On the inner level, he is clearing away bot thoughts.