It's obvious that from the quantum level up to the entire universe the patterns of matter are repeated. An atom, a solar system, a galaxy all have similar forms on an ever increasing scale, but I think the only trait that most of us share with the universe is that we are mostly empty.
Your comparison of individual people to hypothetical universes is interesting, but we would be hasty in linking our perception of physical existence to reality.
And a question, I can see to some extent your view of the multiverse/ individual connection, but where does the anthropic principle come into play?

You experience the way the world is through a very specific set of senses that have evolved through the pressures of the world over millions of years. The world doesn't change for each person or animal, perception of it varies based on the individual.

The anthropic hypothesis or anthropic principle is the notion that a universe must be compatible with the consciousness that observes it. The "weak anthropic principle" just says that the universe seems "fine-tuned" because of survivor bias. It doesn't require there to be multiple universes, necessarily. The "strong anthropic principle" suggests that universes are somehow biased to have sentient life emerge with them -- a view which is more disposed to multiverse theory. Both statements of this principle are, of course, helped by the existence of multiverses.

Regardless ... multiverse theory as I understand it doesn't necessarily suggest that every decision point "branches off" a "new" universe. That would be one possible hypothesis, but not the only one.

Maybe an actual physicist will come along and [in]validate my understanding, but that's how it is at present for me.