As best I can tell, we are a self that "hears" thoughts, feels emotions and sensations, and controls muscles. We can also control our thoughts to a limited extent -- that is, we can decide: I'm going to sit down and think about what I'm going to do next, instead of just rushing out and doing it. But that control is limited. We can NOT control our thoughts to the extent of NOT thinking about a hippopotamus. We seem to have more control over our actions. I can decide not to pet a hippopotamus. What we have the least control over is our emotions and sensations. I'm told that a zen master can control their emotions, through meditation, but I can't. I feel what I feel and I want what I want and, yes, hormones and enzymes have a lot to do with it. But I can control my actions, at least to the extent that if I feel like jumping in front of a train, I can force myself to sit down and think about it instead.