Scientists are educated from a very early time and a very early age to believe that the greater scientist is the scientist who makes discoveries or theories that apply to the greatest ambit of things in the world. And if you've only made a very good theory about snails, or a very good theory about some planets but not about the universe as a whole, or about all the history of humankind, then you have in some sense accepted a lower position in the hierarchy of the fame of science as it's taught to you as a young student.