We geeks like our stuff. Whether it's collector's edition action figures, handmade costume pieces, directors' cut DVDs, bootleg audio recordings, game-tweaked computers or super-lucky dice, we've all got something that we treasure.
And, at least to fellow geeks, it's all pretty cool stuff. I remember the first time I saw a first-edition graphic novel at a friend's house with the author's signature scrawled across the front. My first instinct was to pick it up and admire the autograph, maybe flip through it to check out the story. My friend's gasp when I reached for it made me realized that what was to me, a cool trinket, was one of her prized possessions - an irreplaceable artifact of her geek-ness.
I kicked myself. I should have known better. My years in the Society for Creative Anachronism taught me an important rule about "stuff". "If it ain't yours, don't touch it without asking." Whether at a merchant's booth, as a part of someone's encampment, or in their home - it's always better, safer and more polite to ask before handling someone else's things.
While this is a rule we all should have learned in kindergarten, it was really confirmed for me when I started playing in the SCA. Since the Society (and many other theater or re-enactment groups) put a high emphasis on hand-crafting and creative arts, any item you pick up at an encampment could well be something the owner (or someone else) has invested countless hours of work (or large chunks of money) into. Just because you don't recognize the value immediately, doesn't mean that it's not there.