You can just make yourself interested in whatever you want? If not, then it probably isn't the simplest way.

I would counter, why are you spending time learning something you're not interested in?

Real life usefulness, money, time investment for future use, learning prerequisites for the things you are interested in, etc. There are so many reasons...

I couldn't care less about aspects of my company's business, but I damn sure need to know them in order to get paid.

Simple, but not sufficient since you still need to pair your interest with some methods of study and practice. Which methods of studying are more effective or efficient is the question they're researching.