What Schrödinger’s cat REALLY means

The "many worlds" interpretation results fundamentally from the fact that quantum physicists are not biologists.  A particle can have superposition and can experience as many universes as it wants.  You can't.  Why?  Because you are not an object.  You are a process.  You are a walking, talking ecosystem, at least half nonhuman by cell count, and continually swapping particles with the world around you.  So "you" could exist momentarily in two or more universes simultaneously, but the various versions of you would immediately start dissolving into their respective environments and lose their physical identity.

Actually, this problem of identity was anticipated by the classical Greeks in the Ship of Theseus Paradox.  See  https://en.wikipedia.org/wiki/Ship_of_Theseus