Normally people can randomly experience peek visualizations right before bed or right after waking up. Its clear to reach this dream clarity level of visualization requires the mind to be in a deeply relaxed meditative state, on the edge of conscious. We can take this further, when people maximize performance at a task they are usually in a flow state that is at the edge of relaxation. its a balancing act, only the essentials are kept in awareness, everything else is forgotten, no longer exists.