I'm going to keep this short and just say, I also believe brain chemistry (or body chemistry, since chemicals in the body also affect the brain) may influence or even control our "choices," much as we'd like to think we are always in control. I like to think I'm making my own choices (admittedly, based on experiences I have or haven't had), but the stuff I've read in science suggests that our judgments, influences, experiences, and choices may very well be the result of how chemicals and perhaps health in general work inside us.