Who is having this Dream?

Because you take it for granted that you are real, and exist as such, the assumption is that the world, and the universe, that appear to you is equally real and existent. This is what is meant as the Dream. The contents of the dream are real and exist to the dreamer – including the dreamer, who appears among the contents in the dream.

So, who the “who” is in your question will not be understood while the conviction remains that the dreamer is real, and really exists as such. This is why realizing the implication of nonduality is basically a prerequisite to understanding sunyata: there is no “you”, the you is unreal. When you yourself do not exist as you think you do, what of all that you perceive: how real is that?

No one is having the dream. The dream is illusory, it is not real. The dreamer itself is unreal. Not anything is ever actually happening. In fact, not anything has ever actually existed, in reality, from the very beginning. This is what sunyata means: emptiness is, and has been, the true condition.

So you can see it doesn’t make any difference if you understand any of this, except that – when you do – you take “your life” less seriously. “You” don’t really have a “life”. Neither you, nor life, are real, right now. They only appear to be, to the dreamer.