If you are in high school you probably believe you must know what you want to study before you enter college. Sure, it makes it easier if you do know but one reason to attend college is to find your place in the world. If you begin college on one track and change your mind later you can always take courses in the summer or add an extra class here and there in order to graduate on time.
For some, they graduate and find years later an opportunity which is exactly what they wished to do but didn’t know it. Of course, it’s easier if you do know but its okay if you don’t.