Yo. I read "The Secret Life of Walter Mitty" a long time ago, but I had no idea that it had ever been an expression.
I contest your hormonal explanation for CLE stories on the grounds that I doubt George Lucas was taking oxytocin when he wrote "Phantom Menace." (Oh, but if you read the appendices, you'll find that Estel/Aragorn didn't mean Arwen until he was twenty. She was visiting Galadriel for a few decades.)
Eh. It reads just like a piece of rage, which I suppose is what it is. Still, it could be a lot funnier with some tweakage.
Author's response
The expression 'Walter Mitty' for a Sue-like character has been in use for quite a while now in the regular literary world, but it seems to have missed the fanfic community.
As for oxytocin, believe it or not, men do produce it, but unlike women, who have more of it in their 20s and 30 than when they're older, men produce more of it in their 50s than when they're in their 20s. That's why younger men are more likely to be cavalier about the subject of marriage. When they're older, men are more likely to want a wife around. Oxytocin does several things, but it's noted for being the 'bonding' hormone.
As for the appendices, I have read them, but the point I'm trying to make is that so many people hate Arwen so much, they'll never write her in anywhere as part of Aragorn's life because they want him to marry their OC or because they want to slash him.
This piece is indeed a rant, as I've warned people in the beginning. It was my intention that any humor is going to be secondary to the fist-shaking. Call it the equivalent of a literary prophylactic. If I have prevented the birth of even one single badfic, I have done my duty.