I would say the issue isn't so much "interests" as it is what one finds stimulating. Most people are content to discuss the surface-level, but moving up the intellectual curve, the conversation needs to be deeper in order to be satisfying.
Another problem being that most people cannot handle disagreement. If you want to discuss an idea that often leads to disagreement. True intellectuals relish an opposing viewpoint, whereas the vast majority of people wonder why you're being an asshole. The fact that most people cannot handle respectful disagreement in search of a deeper understanding is a problem they have, but a burden placed on others.
And of course most people who would call themselves "intellectual" are actually in the latter category.
Another problem being that most people cannot handle disagreement. If you want to discuss an idea that often leads to disagreement. True intellectuals relish an opposing viewpoint, whereas the vast majority of people wonder why you're being an asshole. The fact that most people cannot handle respectful disagreement in search of a deeper understanding is a problem they have, but a burden placed on others.
And of course most people who would call themselves "intellectual" are actually in the latter category.