I agree with what you say about high school and heading to college. However, I am about a year or so away from finishing my undergrad in CS, and I have to disagree with the idea that college work is entirely interesting. It is true that most of the classes that directly involve your major are found to be more interesting to the individual. The problem is that colleges will require you to take classes that are not always directly related to your major.

For example, I am currently taking an upper division political science class, but only because it was required. I have no real interest in this course, but my motivation to do the work is to never have to look at it again. I figure if I can do it, and I can do well, then I will never have to sit in this type of class again.

The other issue with college is professors. I have had interesting subjects with the most uninteresting professors. This definitely makes the subject matter more difficult to find interesting. The opposite, however, is great. If I have a subject that I can't stand, but a professor that is very excited and interested in the subject, it will usually get me really motivated to do the work.

Obviously, these are my opinions, so this will vary from person to person. My motivation for doing uninteresting work in college is to have one less obstacle between me and my future goals. I'm sure this motivation can be applied to many other situations.