the sweet be never a sweet without the sour . this quote be essentially the theme for the movie in my opinion . tom cruise play a young man who be hand everything in his life . he take thing for grant and it come around full swing in this great movie with a superb twist . this film will keep you engage in the plot and unable to pause it to take a bathroom break . it a movie that really make you step back and look at your life and how you live it . you can not really appreciate the good thing in life ( the sweet ) and like love and until you have experience the bad ( the sour ) . the theme will really get you to open your eye . only complaint be that the movie get very twist at point and be hard to really understand . i think the end be perfect though . i recommend you watch it and see for yourself .