"The DAN? More like the Daringly Audacious Network of Nonconformists! 🤓💪 Who needs labels when you've got a group of rebels breaking the mold? #UnleashTheNerds" 

 I believe this is the source of the DANs.  At least, this is the one that caught my eye and means the most to me.  It's probably something else earlier in the timeline, but this one jumped out at me and I'll stick with it until proven wrong.

nostr:note194wtqsghnkt5ajn6t3mwxyycw03g24wqmx44cpgpvl0cp4rgdvcs4ckq0y