The Five Geek Social Fallacies were established in 2003 by this dude named Michael Suileabhain-Wilson, and can be read in detail here. They are as follows, in short form:

Geek Social Fallacy #1: Ostracizers Are Evil
Geek Social Fallacy #2: Friends Accept Me As I Am
Geek Social Fallacy #3: Friendship Before All
Geek Social Fallacy #4: Friendship Is Transitive
Geek Social Fallacy #5: Friends Do Everything Together

My friend RockStar and I have come up with another one (as the author has always said is more than possible) which comes up a lot in our lives. It might be a corollary to #5, rather than a fallacy in its own right:

Geek Social Fallacy #6 or #5b: Friends Like All the Same Things.

I definitely am a carrier for this, though my intellectual brain rejects it. Really, people have different tastes and that’s okay. But when someone I cherish, whose opinion matters to me, dislikes something I love, there is a palpable sting. This is, of course, how this fallacy came to be formulated, for RockStar is a man of strong opinions and discerning tastes, whereas I am a woman of strong opinions and occasionally permissive tastes. There are many things I like that he doesn’t like, and it helps that we formulated this rule to remind us that it’s okay for geeks not to geek out over all the same things.

Of course, being sarcastic beggars, it doesn’t exactly play out as:

R: I think [X] is an ultimately shallow and brainless movie.
F: That’s okay, because friends don’t have to like all the same things!

It actually played out:

R: I hate Star Wars.
F: We are no longer friends!

and subsequently:

R: I think [X] is an ultimately shallow and brainless movie.
F: That’s okay, because we aren’t friends.

But we both understand it as meaning the same as the first example.

I’ve been meaning to tell ye about this Fallacy Addendum for some time, but I was spurred into action this morning by yet another Goodreads update e-mail wherein etmorpi gave a horrible rating to yet another Norby book. It’s okay that etmorpi doesn’t enjoy the antics of superpowered, whimsical and supremely confident robots made of barrels of nails. Because people are different, their expectations from literature and entertainment differ, and the landscapes of life and mind that affect any one reading of the same work render it utterly distinct from any other. Friendship is about something more lasting than mere aesthetic symmetry: about compassion, support, and overcoming difference in favor of lasting sympathy.

Or, in other words: Etmorpi, we are no longer friends!