Is my 58-year-old friend’s intense BTS fandom a normal obsession?

or is pretty normal on a 58yrd old woman? There is a friend of mine who for the past 2 years became really obsessed with the K-pop culture, she watches many Korean soap opera and love everything Korean culture. I know korea stuff is very trendy today. ANyway this friends loooves the korean musical group BTS. Since her fascination with the group I dont know she had became obssesed with it, maybe I see it as an obsession or maybe is not an obsession or a parasocial relationship, especially she is 58yr old. I mean I do also ahve my fav famous peopel eitehr group or celebrity and I like to keep track of this favorute famous star but not to the point of collecting stuff and be totally obsessed. This friend made her husband to purchase for her something related to BTS in AMazon some item that was not sold in the country. Then her house keys is ina BTS keychain. She has many other BTS merchandise in her house. She knows all the BTS songs of course. This friend is going with other two friends around her age who also are obsessed like teenagers to a BTS concert in the USA (we are not from the USA). This friend since she decided to plan and attend this concert many months ago, she planned precisely this trip and decided she will exhibit her admiration to BTS to the extreme in some way. 1. She and her friends bought BTS pijamas, 2. They bought special T shirts and items for the concert. 3. They bought other BTS stuff for the trip. 4. She even tattoed a BTS logo in her forearm for real, I mean really a tattoo? 5. The 3 friends polished their nails with BTS logos. 6. For the day of the trip, their departure their airport clothes consist of BTS T shirts. 6. Their suitcases are filled with BTS stickers.

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I know you may like a movie star, a singer and enjoy what they do and follow them in a normal way but to a extreme or obsessed much? I dotn know I have my doubts, specially if you are no longer a teenager as in a teenager I can understand the fandom and obsession is part of being a teenager anyway. I was similar (though not to that extreme) when I was a teenager but not anymore in my adult years in fact I no longer admire the celeb who I crush in my adolescense.
Is my 58-year-old friend’s intense BTS fandom a normal obsession?
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