I like to think of it like this: your thoughtful-self is a pinball. Your body is the pinball machine (which includes the pinball). The player of pinball you can think of as any of the following: the big bang, your parents at moment of conception, the entire universe and its contents. From the perspective of the pinball you know only that you are rolling around maybe on a trajectory, maybe seemingly at random, all over the place, no apparent cause. But your body subconsciously is a very controlled space with a lot of clearly defined physical rules that actually place your thoughts wherever they are at any moment. And of course, the drivers of all of those bodily events are all things our body interacts with.