I always loved my Math and Physics at "school", had really good teachers, which made those subjects fun (which is quiet hard) but I really taught myself anything and everything to do with Computers, and my interests in Medieval History, since my IT and history teachers really were the epitome of boredom.
Of course, with University I studied Games Programming, which was a huge improvement teacher wise than what I had at school. Being taught by someone who was a programmer on games like "Command and Conquer" was a huge inspiration.
A good teacher can really have a huge impact on your studies and interests, not everyone has the avenues to teach themselves a subject, if they aren't getting that in school.