Why I (like Sheldon of “The Big Bang Theory”) believe in the “many worlds” interpretation of quantum theory: It is just too cool to consider that whatever choices we have made in life, in another quantum reality we made the opposite choice, changing our world and our universe completely. Of course the down side of this interpretation is that it makes a joke of free will since all possible choices are made in some alternate reality.
On the other hand, the Copenhagen view is pretty cool too. It gives us godlike powers, even if they are subject to limited conscious control, in shaping the content of reality through our observation of it.
p.s. yes, I am aware of a third interpretation that attempts to reconcile the particle and wave properties of quanta, but it is measurably less cool and therefore rejected absent conclusive proof. Besides, I don’t think Schrodinger’s cat would approve.