https://wiki.lesswrong.com/wiki/The_Quantum_Physics_Sequence
According to Everett / Decoherence interpretation, as explained by Eliezer, atomic or subatomic particles are not physically real—let alone macroscopic objects made with them.
What's physically real is the single amplitude distribution over the infinite-dimensional mathematical space of all possible joint configurations of all the particles in the universe. This distribution—as well as boggling the mind—is complex-valued, continuous, differentiable, and evolving with time according to the well known QM equations. Crucially, it may be more or less factorizable over any given subset of its infinitely many dimensions.
"You" and "me" are just two (more or less) factored subspaces of The amplitude distribution.
Therefore, the question of where do the Born probabilities come from (an open question in QM) is shown to be inextricably linked to an understanding of the physical basis of consciousness (another big open question.) The Born probabilities may represent the "amount of consciousness" (of "you", the observer) that is split among newly factored subspaces, every time "you" get further fragmented, aka. decohered, aka. "entangled" with new blobs of amplitude.
I cannot recommend Eliezer's series of articles highly enough.