Unexpected ending/twist

I thought this was going to be just a plain love story, where the much older guy teaches the young girl the ways of the world, which explained the title. but it wasn't that simple. i actually found parts of the movie believable, and the emotions displayed by the actors genuine.

I really, really did not expect the twist.

spoiler:

i really thought this was going to be some sort of magical movie, since ondine's the name of a nymph.

since robert p. was in this, i thought that this was going to be centered on boy meets girl, they fall in love, they encounter problems, they overcome it and then poof, it's real love. though i didn't like it that much, the ending surprised.

since the plot was interesting, i thought that i'd like it more, but the movie lacked the depth a topic like this should have.

this one made me sad at the end. the trailer kinda gave me the vibe that this was going to be funny and trashy, but it really made me consider what the protagonist was talking about in the film.

i didn't expect this movie to be so depressing because the characters really didn't do or say much to actually make me sad.

pixar did it again! this made me cry and i did not expect the story to go the way it did. the trailer made me think of a different romantic story.

wanted to watch a horror movie, didn't want to watch a family movie.