KEY 2: The only real tangible way of knowing you have free will would be: to be as miserable and boring as possible for a significantly extended period of time, and fail to cooperate with everyone and anyone. Be as negative as possible. Years at the least. Maybe decades. Maybe longer especially if lifespan is extended. Especially in the case this were actually watched by people. In this way, there would be nothing interesting to watch, all plans would be ruined by reacting in boredom or going the opposite direction. If you never make eye contact with people, they aren't there. Not to you, not to the movie. The more boring, the better. The anti-actor. Additionally, if you just killed yourself constantly, but do so in boring and uneventful ways with no expression and half blind. If you obstruct your sight it would lessen the quality of the picture for anyone.
You would eventually end up in jail or more likely the psych ward. But the key here is to not let these places break your will to be boring and give zero fucks. Just perpetually aim to drown yourself and make your situation worse and worse. If you did this for decades or longer, it would be more likely than not you have free will. You must remember to be as boring and uninteresting as possible while this happens else it would backfire. They might even mute your control altogether for a period of time but when you regain control the goal would be to just resume your downward spiral into bleakness, boringness, and disparity.
Further (however to an extreme that knowing free will exists wouldn't even matter anymore because your senses would be impaired): you would gouge out your eyes and refuse implants to restore your vision, or just gouge those out as well. And anytime you woke in a new reality the first thing you would do would be to gouge out your eyes. If you can't see, there's no real interactive experience.
So to genuinely prove you have free will, you would make the actual decision to constantly cut out your eyes, attempt to refuse to eat, and never listen to anything or always try not to.
Written 11/19/18