Own the story

Even though characters and series often fall in and out of slash's favor, mirroring the fickle tastes of popular culture, K/S has been thriving consistently for almost 40 years.

Newsweek

This Newsweek article informs us that an anonymous fan wrote a Don Quixote fic in 1614. I have always seen it as going back to Homeric times and even earlier. Say Homer came through your town and told absolutely awesome stories of a war and of a guy on a long trek. In a week or a month, Homer moves on, but you and your friends and family want to hear more stories. So you start telling your own. And your friend corrects you, saying Patroclus wouldn't act that way, or there is no evidence that Charybdis can swim per se, and Homer would never have told it that way. There you have fanfic, as romantic or dramatic as you like it thankyouverymuch, and you can spend all night around the fire debating the finer points of sea monster locomotion and the age of Achilles.
If you tell these stories enough in your locale, they may turn into your local mythology. I really think Star Trek has that kind of power, as long as people keep telling the stories they want to hear.