As humans, we are a collective bunch of individual cells that are involved in many chemical reactions which results in our behavior. These reactions are equations. By going to AA, you are simply altering your "input" to the equation. By having different inputs, your reactions are more likely to produce a different "output". In short, your new behavior is subject to your new "inputs". This could be nearly anything, but it will be different. This is also why advertisements and corporate media agendas can be so productive. They have direct access to your "inputs", thus increasing their odds of your behavior ending up closer to their desired "output".
Somewhere in there, we also seemingly have some ability to reason, make decisions, and perceive that we have free will. Some or all of this is currently up for scientific debate.