That experience

Every time my sister had this feeling of thinking that things already happened in her life. At most of the phases, she is like "this happened already dude!!!"

Lately, we realise that this phenomenon is called by the french word Deja vu.

So we were all traveling to a place with a traveler previously arranged and planned. As we moved on he started speaking and giving information about the place. As he started the conversation and began a sentence... My sister completed it. No one could understand what was happening. She was literally completing his words. We were surprised to hear it and asked if they planned it before, which they denied.

This was a feeling of familiarity called cryptomnesia. 

Though there are no proven facts about all these... Things like these do happen...