When Henry DeTamble meets Clare Abshire in a Chicago library they both understand that he is a time traveller, but she she knows much more than this about him as he has not yet been to the times and places where they have met before. He falls in love with her, as she has already with him, but his continuing unavoidable absences time travelling - and then returning with increasing knowledge of their future - makes things ever more difficult for Clare.
There has been many times that I, as well as friends of mine, have said that we wished we knew who the right Person for us is... in this movie, Clare knew. She knew from a little girl that she was meant to be with Henry.... This movie takes a peek at the perspective of the loss of free that came with that knowledge. I'm not sure that I would be willing/able to sacrifice my free will to know the end results...