There is no "you" or "self", that's the illusion. The "self" which exercises "free will", that's just another psychologically constructed phenomenon, just like thoughts and ideas and images. If "you" choose to move your hand, it's really just the environment, your senses, and your brain dictating that movement, your sense of self is there as a feeling. Meditation reveals that this is not necessary, this sense of self can be dispelled if you simply investigate it with focused attention.

The above example is not a good one, it's a bit of a straw man actually. The better one is this: pick a film and think of it in your mind...which did you select? Monsters Inc? Animal House? There is no "you" selecting these films, its just your memory module skimming through films you've heard of and seen, then some "preference" circuit is acting to decide which film to "pick" for this exercise.