Not all behaviors are choices. In fact it's easy to go through a day without making any choices at all. Mostly by following habits or instinctive reactions.

There is a reason for this. Making choices constantly is exhausting, especially if you consider all of the possible behaviours. For me, the way to go is to choose your habits. For example: I choose not to spend money on eating out. This a) saves me money, and b) saves me from extra calories in fast food. When pictures of food on a store window tempt me, I only have to appeal to my habit of not eating out. It's barely conscious now. If I forget to pack enough food from home and I find myself hungry, and the ads unusually tempting, I make a choice to reinforce my habit by not buying food, although I am hungry and there is a cost to myself. The same goes for exercising: i maintain a habit of swimming for an hour 3 to 5 times a week, so the question "should I swim after work?" becomes no longer a willpower-draining conscious decision, but an automatic response.

If I were willing to put in the initial energy of choosing to start a new arbitrary habit, I'm pretty sure I could. As my mother has pointed out, in the past I've been able to accomplish pretty much everything I set my mind on (with the exception of becoming the youngest person to swim across Lake Ontario and getting into the military, but both of those plans failed for reasons pretty much outside my control.)

In classical economics, all behaviors are modeled as choices. That's not true of people in practice, but possibly some people choose a higher percentage of their behaviors than other people do. Maybe it's possible to train yourself to make more of your behaviors into choices. (In fact, just learning Econ 101 made me more inclined to consciously choose my behaviors.)

Part of the modelling of everything as choices is that for their purposes they don't care whether the choice happens to be conscious or not. That is an arbitrary distinction that matters more to us for the purpose of personal development and so we can flatter each other's conscious selves by pretending they are especially important.