We know perception is reality but is reality concrete? I think it depends on the individual! What I might feel is a waste of time might be anothers way of taking a mental break. If I did not know that person I would be sure they were lazy because my eyes and ears tell me they are not doing anything but sitting there with a blank look on their face. To my way of thinking that would be concrete when in reality what I think I'm seeing is not the total picture. Now if I heard soothing music and the facial expression I would have to decide what might be going on.