Even if you are not going to use these disciplines in your life, it is important to know at least something about them, because this is what a modern person is expected to know. You might have heard of anecdotic situations, when people were ignorant about obvious simple facts, like that the Earth is a sphere, or that our sun is a star, or that matter consists of atoms and even smaller particles, and so on. Knowing physics and chemistry will allow you to rise above simple explanations of the world we live in, and you will be able to see how all the things in our world are intertwined and interconnected. These disciplines will also teach you not just facts about molecules and elements, but will help you develop abstract thinking and boost your analysis capabilities. And these are the skills that are applicable not just in studying, but almost in any sphere of life.