Sometimes it seems as though I spend almost the entire meditation period doing nothing but daydreaming. Is this just stress being released? Or is it a sign that I am doing something wrong, such as not being aware enough of the mantra? I know we are not supposed to "concentrate" upon the mantra, but how much attention really should I put upon it? When it slips away, not into restful silence but into daydreams, should I knowingly put my attention back on the sound of the mantra, or just let happen whatever happens?