The manner of conviction and sensitivity with which Big B has portrayed the character of a child suffering from progeria in PAA has indeed pushed him to the pedestal as one of the all time greats the world of cinema all over the world could ever see.
It is also one of the interesting facts of the oeuvre of Big B that whenever he has been in a situation where a disease plays an important binding role as the narrative of the film, it has hit bulls' eye. The saga of success associated with diseases in fact began with ANAND where though Amitabh Bachchan did not play a character inflicted with an incurable disease but he had a patient having an incurable disease. The death of Rajesh Khanna in the film and the monologue that Big B entered into with dead Rajesh Khanna announced to the world that a new star has arisen.
It was subsequently followed by MILI where the mysterious disease of Jaya Bachchan had an element of enigma associated with it and the last few minutes of the film turned out to be its most charming moments and it is what made MILI one of the enduring films in his career.
Indeed the films where Big B has enacted the role of a character that has been inflicted with a disease have been defining moments in his career. It could also be owing to the personal pains that he has been besotted with in his life which finds expression in the characters that he enacts through the films.
The flip side of this journey in his career has been that there only was one film where he played the character that carries a physical ailment but it could not strike a chord with the audience as it happened with KABHIE ALVIDA NA KEHNA. Could it be owing to the fact that the ailment of heart condition that he was portraying is now a common disease and therefore the audience could not empathize with the character?
The notion gets strength from his subsequent film BLACK which again turned out to be one of the monumental films in his career where he played the role of a person suffering from Alzheimer's disease and the conviction of being a sufferer of the disease was so much evident that it reemphasized the fact why Big B is one of the greatest actors that Indian cinema has ever produced.
The choice of diseases may be fortuitous in the journey of his career but they were contemporary at the time when they made appearance and the element of rarity of the disease associated with the character could have been the instrumental factor in making the phenomenal performer that he is.