The twist in the tale that you don't see coming (if you have not already watched the trailer a dozen times along with the "Making of Crazy, Stupid, Love.") is that Ryan falls in love, and very dramatically so. This is where the love part of the movie sets in. With a few more twists and turns, the movie ends in a reinforcement of the aforementioned idea of each one destined to have his/her one true love.
It is a lovely movie to watch; touches all those romantic souls (including me) quite deeply.