I would say that most people don't know what they want to do when they first go to college. Also, many people change their major one (or many) times. Usually at least the first year (often two) is spent taking GE (general education) classes. Everyone has to take English, math, science, Humanities, philosophy, Social/behavioral sciences, etc. The reasons for this are two-fold...it makes for a well rounded education, and it helps you decide on a major.