<human>: Give me the gist of the text in a nutshell

I'm a senior in high school, so obviously the answer may just be "most girls and guys have no idea what they're doing at that age."

It's just, a couple weeks ago my gf of 1 year and 4 months or so broke up with me, and I was going to the beach with my friends to try and get over it. Well, surprisingly she showed up as well (she hates the beach), and we strolled along the beach and talked for the first time  since the breakup. She made sure to tell me how one of our mutual friends tried making moves on her. She clearly emphasized how this whole thing wasn't her scene and she was taken aback by all the debauchery and she "was just here to say she experienced it." 

So, now that she's home, she's posting on social media talking about how great it was and how it was such a blast, and now she insists on not talking to me. 
Why? I can't shake the feeling she's not living for herself, but instead living for her own persona/image.
<bot>: don't understand a certain girl, and as I can't talk to her at the moment, I'm asking other people in an effort to understand.