One thing I would say in relation to taking a gap year between high school and university is that after a year of not much study, you can find it hard to knuckle down to university life. Another is that you might find that what you want to do and what you think you want to do might not be the same thing. Some people leave school and say that they want to do this course and have this job, but decide after a year at university that it's not what they want after all. Some might drop out, spend a bit of time travelling or whatever, and then return to university to do a different course.