Quantum interference does not affect the behavior of larger more complex objects (like human beings) the way it does for individual elementary particles due to entanglement. That’s why you don’t observe the concepts/theories in quantum mechanics like superposition and the multiverse in everyday life. The Beginning of Infinity, however, describes some scenarios where it could.
Take for instance a neutron traveling across the universe. Due to interference it’s position and speed make it more like a cloud by the time it reaches Earth. It hits every point on the Earth and in our autonomous history it strikes a single cell of a person and damages their DNA causing cancer. This would clearly have an impact at a macro level and even world-altering consequences.