reading a book and watching it on celluloid are completely different experiences,and hence,usually,modifications need to be made while adapting a book to screen.godfather,though a brilliant movie,did feel sluggish at parts.on the other hand we have chris nolans memento(adapted from his brothers novel memento mori)which changed the plot to a large extent(the conclusions to the celluloid version and the novels are completely different)and i dare say,worked wonders for the plot.the same for chris nolans 'th prestige'(adapted fron priests book by the same name).however,sadly,literary adaptations are a rarity in bollywood(sadly) with vishal bharadwaj being the only notable exception.wish the bollywood directors adapted more literary works.that might just bring a bit more variety into bollywood movies.