on the surface, everyone's condemning it for its 'inspired' storyline. but then, even Shakespeare picked up stories from the common database. i am not comparing it to his work.. you could point a finger at its not so original storyline, but credit is due where it is due. the movie is refreshing in the treatment it gives the girl-guy thing. it incorporates a cartoon strip = animation smoothly. and, not only does the movie manage to stay restrained almost throughout without following the general "second half" drag, it also deals with more than just the "cover story" or theme.
at its base is this endearingly constant bickering and loving relationship between karan and rhea. but go a little deeper and you see the sub plots of the rishi kapoor-rati agnihotri marriage-that-didn't-work, and the lonely kirron kher. kunal kohli deals with the theme of loneliness, and puts his point forward subtly in their stories. no one can live alone. and finding a way to make relationships work - is in our hands after all - as rati says towards the end - god might not give us a second chance, but we have to find it for ourselves.
the movie is realistic enough - contrary to what some of the obtuse commentors have posted already. and definitely a complete whole structure. minor glitches notwithstanding, it's a delightfully entertaining and heartwarming movie.