Did you "get it"? Can you simultaneously be asleep and awake? I've been writing about "believing some thought-images are real"; enough already, you think? What's the 'big deal'?
But did you get the part that "at the moment of believing a image is real"- you don't recognize doing it? If you did, it would be like waking up and no longer doing it.
Recognizing 'believing a image is real' "breaks the spell" of believing. You can test this yourself, instead of using a thought-image, use a onion and believe it's a apple. If you sincerely believe it's a apple, you can bite, chew and swallow and it will taste like apple and your eyes won't tear. As long as you 'know' it's a onion you cant/won't believe it's a apple. Only by ruse or hypnosis would you sincerely believe the onion is apple. That's the placebo effect. The subject 'believes' the inert pill is medicine. If told it's only a sugar pill, would their involuntary react to the pill? The subject reacts to their belief, even though it's false. Another example; " I thought the gun was empty." That's like waking up, waking up to the fact that a false thought was believed.
When you don't recognize believing a thought is true, real; your not in charge of your involuntary reactions (emotions), our involuntary is 'hard-wired' to react to perceptions of/from environment. Belief-perceptions are just as automatically reacted to; our involuntary does not,-cannot distinguish the difference.
As a child, were you ever afraid of the "boogyman"? You've been doing this for a long time, only the images been changing.(you stopped believing boogyman, how about other images?)