So the basic solipsist proposition seems to entail not only that you are the dreamer of this whole thing, but that you have also forgotten (possibly by intention) most of yourself.
I think we have all had elaborate dreams of alternate realities where we forgot who we really are.
Regarding the perspective of solipsism, it is not clear to me that, in a dream, imagined people are any less "real" than myself in the dream. They, with their own personal histories and personalities, exist somewhere in my brain just as my consciousness does, and I don't think I could distinguish between them (as figments) and me (as "real") if I never woke up. In the dream, we might as well all be figments, imagined by the same mind.
How one gets to the psychonaut's version of solipsism is an interesting topic, now that I think about it. For me, it occurs after many realizations of interconnectedness. Each realization makes it harder and harder for me to define clear boundaries between my brain and the matter surrounding it. Eventually, my mind has expanded to encompass other people and objects. By the end, my mind seems universal. Of course, by then, the definition of "me" has changed, so by "my mind" I do not mean the brain of this primate that you speak of.
I think that otherwise inanimate objects can have subjective experience, and we can thus empathize with and mentalize such objects. So perhaps the mind-of-the-universe perception results from our ability to imagine reality not only from the perspectives of other people, but also from that of objects, groups of objects, and the universe itself. Such imaginings cause me to see my mind, and the minds of others, as manifestations of the self-consciousness of reality itself. Our conversation is like an internal dialogue in a transcendentally subjective being.