Why did she act like she doesn't know me when we've talked before?

Anonymous
I knew this girl in my class last semester. We used to talk all the time, and I would help her with her classwork more than anyone else. Now, we don't have any classes together, and when we pass by each other, it's like she has never seen me before. She doesn't glace at me, smile, or anything. Like I'm a stranger. I mean, we were in class together for over four months AND we talked to each other a lot, about things besides class work. She knows me, and now acts like she doesn't. Why?
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+1 y
She's definitely NOT SHY. She talks a lot and is very very popular at school. She would ramble on and on about her weekends and all that stuff. Now, she doesn't even glance at me.
Why did she act like she doesn't know me when we've talked before?
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