If you become lucid in a dream where you have a body, you will almost always be able to control your body. However, you might not manage to do anything else. Do not worry, though, most people have no problem with jumping extremely high or flying in a lucid dream! - On the other hand, parts of your brain are less active while dreaming, which can lead to dream/trance logic and sometimes choices you will later regret. For example, you might choose to continue your lucid dream, although you know that once you wake you will only remember half of it. Once you wake up, you may wish that you had stopped your dream.