Also, I personally believe that there is one thing your brain cannot simulate. And that is 'not knowing'. This is how I practice my reality checks. In reality, there are an infinite number of factors that you can't anticipate. Say I was dreaming that i was lying in bed. And I got up and walked out the door. If it were reality, I wouldnt have known that there was a pile of laundry on the ground. I would have tripped and fell. That moment when you trip you think to yourself "what did I just trip on?!". You would never experience that in a dream. Because somewhere in your mind you know everything that can happen.