Cachers are not, I repeat, NOT, like trekkies.
I am sorry, but I have gotten quite a ration of crap from my friends who think I am an uber-nerd for geocaching. Those friends, of course, are only the ones that HAVEN'T come caching with me yet, haha. The ones that have, are all converts.
Trekkies watch a TV show. Cachers explore places they have never seen, solve puzzles, hike, swim, dive, climb, repel, and look absolutely ridiculous at times to find some crazy fake treasures. Sounds pretty different to me, and the sills learned while geocaching (using a compass, GPS, following trails, etc) can actually have some pretty good use in muggle life.
Which leads me to my next point, people def think we are nerds for using fricken Harry Potter slang in our hobby, lol.