Free will is a tricky subject. It certainly feels like I can deliberate and come to a free choice, by abstracting decisions from my immediate and prior influences.

I have previously tried to come to terms with not having free will, and it left me feeling stripped of any agency / control, utterly depressed, demotivated, and incapable of doing anything. If there is no reason for my actions, other than the initial state of the universe evolving forward in time, then there is no point to anything. Most people can't live like that.

Could there be an alternative explanation, based on unknown physics; selecting between different permissible universes?

I heard an argument from Terence McKenna that I liked, along the lines of: You should choose to believe in free will, because it appears that we have it. If you choose to believe in it, and it doesn't exist, then you had no choice but to believe in it anyway.