You're totally not an idiot!
You just happen to spend your time with people who maybe don't share your interests.

That art bit of conversation? That'd be excellent info to share and talk about with someone who's interested in art and art history! But maybe not interesting or understood by someone who would never be caught dead in an Art Gallery.
I get really excited by silly sorts of things too - and yeah, sometimes people around me reaaalllly don't get it. I tend to inform them that it's ok if THEY don't get it, because I know it's awesome and they're totally missing out

If they show some interest in the fact that I'm excited, then I'll try to explain it to them.
Nothing at all to feel like an idiot about

You're just passionate!