Why Should I Learn This?

I was talking with my wife (which is a teacher) about how to make students want to learn a specific subject. My solution to the problem was that you have to make the student understand how learning the subject at hand can improve the quality of something they already enjoy doing. I sat down for some moments and jotted up this class diagram:

Class Diagram

Basically, you have a many-to-many relationship between subject and interests. Subjects can be history, geometry, math, grammar, music etc. Interests can be soccer, music, sports, etc. The connection between them lists the reasons for learning that specific subject based on your hobbies or interests. A website that easily allows lookup of reasons (and additions) could be a good resource for students, teachers and parents that regularly enter into the discussion mentioned in the title. Want to help make it a reality?