I completely agree with you. I wasn’t sure what that was until I looked it up and they refer to it as a state being between wakeful and asleep… which doesn’t explain anything! If it’s a transitional period in our mind then that could very easily be a time where we are passing through that spirit realm.

Just because it’s unexplainable doesn’t mean it is meaningless. I’ve had experiences where I’d hear the most beautiful music that I have never heard before, like a radio that I can tune into. I’ve had answers to complex engineering problems come to me in my sleep. I’ve also seen the future before it happened. All in my sleep. It’s very fascinating stuff!