Can somebody explain the whole muffin-obsessed Derpy fanon to me?

I have a question: how does a character who says a word once get labeled as obsessed as what that character said, like when Derpy allegedly said “muffin” in Applebuck Season? That would be like me saying “pizza” when I see it and then getting labeled as pizza-obsessed (and I friggin love pizza). And how does the clip on her bags make her muffin-obsessed? It’s like the only thing about Derpy is muffins, mail, and her fanon daughter (which is obviously not canon). It amazes me that there are bronies who would love to hang with Derpy and make muffins all day, because if you met someone like that in real life, you wouldn’t want to hangout with that person, since all that person would talk about is muffins, making him or her annoying and boring. Really, it’s only because it’s Derpy that they’d want to hang. I mean, muffins could be her favorite food, but that doesn’t mean she has to be obsessed with them.
 
Anyone care to explain?

Well, that’s just fanon. As crazy as it might be, you won’t be ever able to change it because fans would shoot you down for thinking differently. Fanon can be very strange at times.

The wonderful yet strange world of fanon.  
Something i will never fully understand.

Muffins was her first word in the show I believe, so her and muffins became something special to a lot of fans. The extensiveness of the fanon surrounding it has little to do with the show itself, but rather the fans expanding on something that would otherwise be insignificant.

The thing is that the muffin obsession is now canon, along with being a mailmare.

@Itsthinking  
So a trading card, merchandise and a bunch of comics make it canon, even if the obsession isn’t explicitly seen or mentioned in the show? Damn…

@Chief Keef  
Sadly, probably. And Derpy is my favorite background personality, but I don’t really like both her alleged “canon personality” and her fanon personality. Oh well.

@PrisonedMuffin Then what should it be oh wise purveyor of pony perfection?  
I’ve really only encountered two fandoms for Derpy, and they’ve pretty much become interlinked fanon-wise, though canon appears to have gone with Dinky being completely unrelated. Which leaves…Only one.

@Niggoslav_Krawczyk  

 

To think that one word by one can define one’s personality. So whenever I say “burger” when I see a delicious looking burger, by brony logic, I must be a completely and totally burger-obsessed retard, when in reality, our favorite foods are not our obsessions.

@PrisonedMuffin
 
…to be fair, the “baked bads” looked far from edible to start with and “all the ponies in this town are crazy” to think that what they were looking at would be a delicious treat; they really only had themselves to blame for becoming hospitalized.

@archestereo  
I guess they are crazy.

Poor Derpy.

@PrisonedMuffin  
But you’re a real person. Not a background cartoon character that was never intended to have a personality in the first place.

@Too_Offensive  
No, I am Tyler, The Creator, bitch (not srs).