Personal preferences definitely enter into deciding which is "interesting." Biology intrigues many people because they are affected by their own genetic makeups and are interested in animals and plants. When people look around them, biological elements are salient. However, chemistry is also very interesting as is physics to those to whom it appeals. Chemical advances affect people in many ways: medicine, cleaners, fabrics, cosmetics, etc. Physics has an impact on people, too, especially in day-to-day activities such as driving and flying in jets, or when one goes boating. Simply put, the more educated one is in a field of science, one is usually more interested in it.