Why do some people get obsessed with another person wanting to know everything about them?

For example: There was a very beautiful girl back when I was in college, that some other girls that I remember, wanted to be like her, see her every day in a lecture, see everything she wore to college every single day, her hair, her makeup, skin, body shape etc.

There was this girl in particular that I could tell that she got all hyped up, whenever she saw that beautiful girl walk in with her long hair and cute outfits.

Why do some women/men cause such an impact, that makes other people want to know everything about them? Is this pure idealization

Have you seen something like this? I’ve never understood why this happens.Btw it has happened to me as well, a little weird.

I would say perhaps it has to do with having a low self esteem ?