When J.K Rowling began writing Harry Potter in the mid 90's perhaps she had not imagined the magnitude of impact it would have on the entire world of fiction stories. Harry Potter books are a legend and for those who were potter fans associate a large frame of childhood to Harry Potter books and movies.
Coming to the first film adaptation which is The Sorcerer's Stone or Philosopher's Stone the casting of the child actors were pitch perfect. They fit the bill to the T. Book lovers could associate the role of Harry, Ron and Hermione in the three lead actors. The story was appropriately addapted from the book showcasing every vital incidents and introducing the characters that would go on to play an important role in the final chapter of Deathly Hallows.
I have grown up watching and reading Harry Potter movies and books respectively and will remain a die hard fan forever.
