What are some reasons why she would ghost me suddenly and then after a week or so come back like everything is fine?

We hit it off, got close, it seemed like we just got each other and the conversations flowed easily. Then she ghosted me which hurt and a week or so later she comes back acting like everything is fine. She knows she hurt me but still gives no explanation even if I ask. What could be some reasons?
What are some reasons why she would ghost me suddenly and then after a week or so come back like everything is fine?
Post Opinion