First, watch this:
Having watched it, you may now have an idea what the ‘many worlds’ hypothesis is about.
Focusing on the Schrödinger’s Cat example: when the box is opened, the universe splits into two; one in which the cat is dead, and the other in which the cat is alive. Each person continues in their own copy of the universe, oblivious to the other.
Let’s take it one step further. As explained, the entire universe is entangled. When an ‘observer’ (you) measures (interacts with) any part of it, a new branching occurs. This must mean that every time your consciousness becomes aware of some aspect of your surroundings, a new universe branch appears; one that reflects the information you perceived.
A new universe is thus created every time you make a decision, no matter how trivial.
Now: choose an arm, left or right. Raise that arm above your head, then bring it back down again. You freely chose which arm to raise, yes? I didn’t influence you at all. But consider the possibility that you had chosen the other arm instead: there’s another you, in another universe, who raised that other arm… and that other you, like you, believes that they chose that arm of their own ‘free will’. (Or, perhaps you chose not to raise either arm!)
If ‘many worlds’ is true, this would completely reconcile the free will versus fate conundrum.
Perhaps those who say that we create our own reality are absolutely right….