When your experience with school has always been one of coercion this is the most difficult question to answer. You've never been told that you can choose what you want to learn.
But, in the "real world" you can and must choose what you want to learn. It's a shame that many students are put through 12 years of schooling and come out with no idea what they really want to learn. In fact, they often have no interest in learning anything.
As children, these students were not like this at all. They were like most children: curious, inquisitive, interested in learning. What happened in the ensuing 12 years?