Meditation is what remains when the activity of the mind, the overlay of thought onto pure, ever-present experience, dissolves. And meditation is what was prior to that activity.
An incense burner, robe, and meditation cushion are not required. You can do it anywhere, but since it is not an activity, you cannot do it anywhere.
It is the sky remembering it is not the clouds, but the sky in which all of the clouds appear. And then it remembers it is the clouds too, since they are made of nothing but sky.