So now you might be tempted to just ignore the question, ignore the mystery of free will. Say "Oh, well, it's just an historical anecdote. It's sophomoric. It's a question with no answer. Just forget about it." But the question keeps staring you right in the face. You think about individuality for example, who you are. Who you are is mostly a matter of the free choices that you make.
In the history of science, Laplace's demon is a thought experiment involving a hypothetical "demon" envisioned in 1814 by Pierre-Simon Laplace such that if it knew the precise location and momentum of every atom in the universe then it could use Newton's laws to reveal the entire course of cosmic events, past and future.