There is no good reason to quit school. You've only got 2 years left. If people aren't taking your ideas seriously, they really won't think you're very smart quitting school. That doesn't mean you won't be able to start your own business, you just have to be patient and wait a little bit longer, UNLESS, it's something you can do with minimal start up costs and can do it part-time after school. DO NOT QUIT SCHOOL! That is stupid.