Exactly what are dreams? What is the nature of existence? These are fun questions to ponder. Tackling the subject is a fun, engaging routine for the mind. Scientists explanations for the start of the universe always seem odd. A big bang that came from nothing? Our universe starting from a previous universe? I'm of the mindset that the universe is way too big and unlimited for our comprehension. I support research into the building blocks of time, space and matter. It's not going to answer why or how it all started, but we can tell what it is made up of and possibly bend it to our whim or needs.
This ties into dreams because dreams might be our mind's way of jumping universes (multiverse idea). In our dreams, we are still ourselves. In our dreams, we have sense like we do in our awakened state. Our mind makes matter real. Without our brain processing the inputs, the matter would not matter. It would exist, but not in our mindspace. The observer and observed combine to make it real. That happens in our dreams. Does our mind not make it real there? I believe it does.
I also believe that the connection to other universes is through our mind. That 3 lb universe is an even bigger mystery to scientists than outer space. Maybe dreams are the brain connecting us to another universe. The brain is the pathway and our dream state is our time in that specific universe. This could be an explanation for how we sometimes fall back into a dream or have the same dream (or a similar dream) twice or thrice. This could also be why we have different rules for the physical world in different dreams. We've all had that dream we could fly, barely see, have increased strength or move quicker. I do not see science answering questions about dreams anytime soon, and wild speculation should be encouraged. Multiverse theory feels right in this instance.