why was this girl looking at me?

[Arkchemist]

I dont see her anymore since we both graduated but... why did she looked at me on so many occassions and then would ignore me?

In 11th grade we had a class together where we never once interacted. She did her stuff and I did mine. In fact, at the end of the year, she was qalking past me and looked at me, but I figured whatever...

12th grade starts and about three days into school I see her walking with some guy. She looks at me for a like a second while she walks and then looks away. A few days later I'm at the mall and Im coming out and she's coming out and we saw each other as we both walked past each other. We never spoke or anything. I was at the schools office once and she was leaving the office and came back to get a set of keys she forgot and stood right next to me, though she just looked straight ahead ( i thought she was avoiding looking at me because she just stared forward...weird) Another time at the same office, I looked back to see the clock on the wall and she was sitting there looking in my direction. She then turned to her phone to text or something when I saw her, though she didn't looked spooked or embarrased. Another time I'm at a Starbucks line and after I place my order, I notice she's next in line. She was however texting and decided to call someone instead of talking to me...another time I'm at the mall and I'm coming in and she's heading out with a friend and we both see each other. Another time at the same. At the mall during Christmas she noticed me and looked at me while she was walking. She put sappy stuff on her phone as well, saying stuff like how she had been thinking of someone lately and how she shouldn't forget about him, or how there r plenty of fish in the sea. She even complained with some guy about how she was giving up on someone because that person never made an attempt to do something and she did all she could? Now, this girl is popular and last year she flirted with other guys and even approached them first when she though they were attractive( we had a class together, but again we never interacted)

On Twitter, she once complained about a person who never approached her and how she did all she could but he never did anything. She also retweeted a pic of a message saying how she's been thinking about someone lately and how she needs to forget about that person...and she stated how scary that message was.

The thing that bothered me the most is that she once took a pic of her best male friend and they were like super cuddling, she was kinda kissing his D through his pants lol, though that same guy asked her if she had a bf and she said she was taken(though she never posted pics or talked about her bf before) I know this type of girl is not right but I still want to know why would she look at me on so many occassions like the ones I listed above.

My friend told me it was all coincidence. That this girl couldn't have liked me. I mean, a super popular girl liking me but didn't approach me when she approached other dudes more attractive, wtf, right?

Why did she looked at me so much? Also, she approaches other better looking males than me and is experienced with relationships so if she liked me why didn't she do anything?