idk, i thought it was fan + kingdom, or fanatic + domain??

The OED also rejects your portmanteau hypothesis, though I suppose sportswriters from the 1900s might’ve been trying to be quirky and different when they coined fandom from the productive derivational suffix -dom, which the OED also gives copies examples of throughout the 1800s (including BA-dom, old fogey-dom, blizzard-dom and theater-dom.

The Minneapolis Journal published a sports column called “Matters in Fandom” in 1892.

Use for non-sports fans dates back to at least the 1910s for film fans…

And the 1940s for science fiction fans…

paranoia

control freakism

sense of self-worth so low that it loops back around into being totally dismissive of everyone else

a warm-hearted kind center beneath 200 protective walls of bitterness that doesn't actually make the bitterness better in any way at all even a little bit

bisexuality

crushing feelings of responsibility

zero understanding of own bodily autonomy that bleeds out and affects how they treat others

a lil petty vindictive sadism they maybe don't wanna look at too hard or acknowledge

full self-awareness of all their most negative traits without working to fix those traits at all

internalized misogyny

a mysterious undefinable hunger that cannot / should not / must not ever be sated