As you can tell from my username, I am an experienced lucid dreamer. One time I managed to have forty-something lucid dreams in a single month. But I haven't had one in a while, because I haven't been thinking about lucid dreaming much in my waking life (too much other shit to worry about).

And yes, it is hard to control your dreams. What happens in your dreams is usually what you expect to happen, so controlling events in your environment entails consciously changing your expectations of what is going to happen. In real life we aren't used to doing that, since we try to form our expectations on what we know to be real instead of what we wish to be real.