So many of us try to define who we are based on what we do. I believe in the opposite, that who we are defines what we do. I feel like this is an important distinction to make, because people do a lot of things due to external pressure to try to be something they are not, in hopes that it will change who they are, and people get very afraid of doing certain things, because they are afraid it will change who they are. There is a lot of subtlety here, and I will try to handle it with as much care as I can. Ideas are delicate, and sometimes require gentle handling to make it to their destination intact. Keep in mind that I'm speaking from my own experience, and that the ideas expressed here are the conclusion I've come to from ruminating on my experience. I don't mean to say that I am absolutely right, simply that this is how I currently see things.
One only understands the things that one tames,” said the fox. “Men have no more time to understand anything. They buy things all ready made at the shops. But there is no shop anywhere where one can buy friendship, and so men have no friends any more. If you want a friend, tame me...The issue here is that you cannot really know a person based on what they do. It's much too simplistic to view them that way. Of course, sometimes we have to, simply to be able to communicate at all - we have to settle for a label or a generalization. But in general, the only way to know a person, is to know the person. In order to understand a person, one must spend time with them and get deeper than just doing similar things. I can participate in many of the same activities as another person: let's say cycling, photography, cooking; and also have many of the same character traits: let's say sensitive, opinionated, active sense of justice. This will not mean that we are the same. We could be vastly different people, despite these outward similarities, and this is what I think really belies the idea of our actions changing us on some fundamental level.
So I guess it kind of comes down to this, for me. We are who we are, and over the course of our lives, we can try to stifle and cover up who we are (and there is sometimes immense outside pressure to do just that), or we can nurture and grow it, and more fully develop it. Either way, we are either simply hiding or uncovering the essence that is already there, not changing it.