I like Little Mix, the popular British girl group.

But am I a fan?
At what point are you considered a fan? Do you need to know all members’ birthdays? Do you need to have memorized all the songs? Do you need to know what each member likes or dislikes? Or, can you just have bought all the CDs and listened to most of the songs?
I once took a quiz Little-Mix themed asking all kinds of questions to determine how much of a fan you are. Or Mixer, as they’re called.
I did very horribly because I didn’t know things like whose birthday is first, which Little Mix song is included in which CD, who owns a pet, and so on.
But being shamed as “not a fan” felt a bit much.
By the way,
Fan is short for Fanatic.
FAN: A person who has a strong interest in or admiration for a particular person or thing.
abbreviation of fanatic
(Oxford Dictionaries)
These are the people who will jump up on stage while the singer is performing just to be able to touch their leg or something. These are the people who will find a tissue that their idol threw away and keep it in a plastic baggie in their desk drawer. Or sell it on eBay.
These people are fanatics.
So, saying “I’m not a fanatic” is like saying “I’m not a fan” because fan is short for fanatic.
I don’t like to say I’m not a fan. It sounds like I’m saying, “Well, I do listen to Little Mix but I don’t like them THAT much. In fact, I’m not THAT fond of them.”
I do like them. I do like their music and I’ve probably watched their X Factor journey more than a few times and teared up.

I have all their CDs and I love watching their music videos from time to time. I also know all their names and I might recognize their last names if I saw them. (Jade Thirwall, Jessy idk last name, Perrie not her either, Leigh-Anne I have no clue)

How can anyone say I’m not a fan? I am a fan. I like Little Mix. But I’m not an extreme fan.
Probably the word “fan” today is a pretty broad term pointing to the extreme (keeping idols’ trash) and to the less extreme (own all their CDs).
You can be a fan of so-and-so if you keep their trash and follow them around tour. You can also be a fan if you just buy their CDs and listen to their music.
Fan does not always mean fanatic anymore. It can mean “I like them”, “I wanna own some of their merch”, “I wanna subscribe to them (YouTube)”.
It also means, “I wanna stalk them on social media (extreme)”, “I wanna keep pieces of their hair in my drawer (extreme)”, “I have a shrine for them in my room (extreme)”.
I will say now that I am a Little Mix fan. I like them. But I am not a Mixer.
Not saying Mixers are fanatics but I think a true Mixer will have aced that quiz.