This is the scenario that plays out in my head when I imagine explaining my interest in keyboards:
Co-worker: So every time I walk into your office I see a new keyboard... What's up with that?
Me: Allow me to preface my response by saying I'm a complete nerd and keyboards just fascinate me...
Co-worker: blank stare
Me: ...And there's these ways you can make a keyboard your own, like choosing your layout, case, key caps, even the switches, all providing a more interesting, personalized, typing experience than a typical keyboard...
Co-worker: blank stare
Me: ...And it's a practical hobby because it's something I use every day for work...
Co-worker: blank stare
Me: ...No, wait, you're not understanding. See, back in the 1980s keyboards were manufactured really well, and companies like IBM made beautiful keyboards, and they had these really nice switches like buckling springs and Alps, and Cherry and it was really enjoyable to use them. But then somewhere along the way, keyboards were commoditized and cheapified to the point that nowadays they're just plastic and rubber disposable crap, and they're basically depressing to use...
Co-worker: blank stare
Me: And then this really amazing community of enthusiasts came along and decided to pool their resources together to design their own keyboards that are much better than anything you can buy off the shelf, and they're like these little works of art sitting on your desk, and they're so enjoyable to type on, and there's so many really interesting thing going on...
Co-worker: blank stare
Me: Never mind