Her feelings change because they are simply temporary emotions.
A lot of it is determined by how she feels that day, what her mood may be or how hopeful she is about something.
She may need to experience constant excitement to keep her feelings consistent.
If she is not experiencing that level of excitement, she may become bored or even unhappy with her interaction with you.
She feeds off of that particular feeling of curiosity and anticipation.
She needs to be able to anticipate and even visualize how things are going to go with you.
Her feelings start to change when she isn’t certain of where she is going with you.
She will feel this way because of something you may have forgotten to say or do.
There is an expectation that she has that wasn’t met and now her feelings are changing.
She will also have her feelings changing when she gets too excited.
A girl could get misled by her excitement about a relationship or someone she is seeing.
She can easily allow this excitement to get the best of her.
As a result, she begins to set expectations for the relationship very early on.
She really allows her imagination to go wild with these expectations.
Oftentimes, these expectations are not realistic.
However, her feelings are getting the best of her.
She can’t contain them.
They are going to places that are making her feel even more excited.
She may daydream about what she wants.
She may fantasize about the hopes that she has for this new relationship.
With these set expectations, she believes that the relationship should go in a particular direction and at a particular pace.
When the reality inevitably happens, she is disappointed.
She is disappointed that the relationship isn’t going the way she sees it in her head.
She is disappointed that you haven’t done or said certain things that she was certain you would say by this point.
As a result, her feelings change very quickly.
She starts lacking motivation. She begins to believe that you may not be the right one for her.
Another reason why her feelings change so quickly is because she never knew what she wanted in the first place.
She may have told herself that she wanted you.
She may have told herself that your character and appearance is what she finds appealing.
However, she comes to realize that she really doesn’t know what she likes or wants at this time.
She may be discovering herself and her tastes.
She may not know what she really prefers.
Initially, you seemed to fit the perfect description.
You seemed to have the appearance and the personality.
However, now she questions her tastes.
She may have even noticed someone else who captured her attention and he may look totally different from what she thought she liked in a guy both in appearance and character.
She may want to investigate what it would be like to interact with him instead of you at this time.