Maybe you are not subservient to your brain. But at the risk of sounding esoteric here, maybe you don't know that you're subservient to it.
People are highly habitual creatures. People tend to repeat their behavior in an extremely patternistic ways. People tend to accept their realities in life, in relationships, in jobs, in situations, rather than to create the realities. And creating a reality comes from an honest deviation from the history or perceived personality that one may identify with in their "mind."
It's very hard to get my point across in language because it is not an idea that can be communicated through words so much as it is an idea that can be brought to fruition through acceptance of reality, and acceptance that history is exactly that, history. And the future is exactly that, the future, it doesn't exist.
Reality is not the collective filter of memories and fears that one's mind tends to base reality on. That's my point. Reality is now, not yesterday, not tomorrow, and the mind, and the brain for that matter tend to wallow in the non-present, the one place it doesn't have access to.