How much of your behavior do you really control?
The easiest way to figure this out is to watch your breathing. You can certainly control your breath to a certain extent. You can hold your breath, and you can accelerate your breathing.
Then stop watching your breath and start thinking of something else. When you stop thinking about that something else to go back to watching your breath, guess what—you’ll find you’re still breathing automatically.
It’s very difficult to truly distinguish between happening and doing, even when you believe you’re doing something seemingly completely deliberately.