I just finished watching Serendipity and I did not like how it was presented. I did not like the parts that seemed utterly useless... I did not get why the director decided to always show the traffic or why there were a lot of things that were shot in fast forward. It just did not make much sense to me.
However, I liked the story. While it may sound far fetched, sometimes life is hard to explain like the movie.
Life is complicated like that and sometimes we just have to trust where our feet take us.