Eminem's Stan was fictional but stans are a real phenomenon

Another new (to me) term I happened upon recently is "stan". Not as in Pakistan, Kyrgyzstan and Turkmenistan, where the "-stan" just means "land" or "place of". But as in "look at that group of stans lining up for hours just to see a boy band".
The Urban Dictionary defines a stan as "a crazed and/or obsessed fan", used to describe a fan who goes to great lengths to obsess over a celebrity. So, not just a fan, not just a superfan, but a stan.
You can think of it as portmanteau word combining "stalker" and "fan", but the word actually comes from the name of the (fictional) central character of an Eminem song, released in 2000, who is so obsessed with Slim Shady (Eminem's alter ego) that he kills himself and his wife when the rap star does not respond to his letters.
Eminem's Stan was a fictional figure, but some music fans do go to some extraordinary lengths in their obsessive adulation of pop stars. And yes, celebrities do receive a lot of desperate, and often quite disturbing, mail from their fans/stans. Korean K-pop boy bands in particular seem to be prone to this kind of excessive adulation.
The word can now be found in the Oxford Engish Dictionary and the Merriam-Webster Dictionary.