I plead guilty because I seem to be the only critic who did not watch Forrest Gump, except in bits and snatches during an international conference on "Sound in Cinema" in London. The film was analysed as one of the best examples of sound design running across several tracks at every turn. So, fortunately or not so fortunately, this gives me the opportunity to view Amir Khan's Laal Singh Chaddha with an open mind not haunted by the shadows of the inspiration.

For me, Laal Singh Chaddha is an independent film from one of my favourite production houses – that of Amir Khan who has almost always presented us with unique perspectives on people and relationships. Most importantly, the agenda is woven subtly yet powerfully into the narrative and the characters of his films. Of late, his films might not have hit the mass market, but that cannot strip him of his distinctive identity as a committed filmmaker and actor par excellence.

But this critic really wishes he did not need to fall back on an Indian adaptation of a much-acclaimed and awarded Forrest Gump. That film is now a classic both in terms of cinema as a technical miracle, and also in terms of cinema as a character-driven narrative device you carry with you outside the theatre.

Khan has done it before when he acted in Aditya Chopra-produced Dhoom 3 which was accused of being a rip-off from Christopher Nolan's The Prestige, with writer-director Vijay Krishna Acharya adding a further twist to it. Poor Katrina Kaif was reduced to a glamourised extra. It was a thumping box office success though it just did not carry the "Amir Khan'' signature.

Dhoom 3 was screened during the 2014 International Film Festival of India in the Celebrating Dance in Indian Cinema section. Yet, it was a watered-down music-and-dance version of the very serious and dark The Prestige.

Laal Singh Chaddha is structured, for the first half, over a train journey between Pathankot and Chandigarh during which the simple-minded Laal begins to narrate his life story. He also unfolds his mother's philosophy of comparing life to "gol gappas", which never mind how full you are, you keep craving more.

No one in the second-class non-AC compartment seems interested to begin, but slowly, all the passengers gather around Laal and listen. But the minute he reveals that he is the administrative head and the proprietor of a globally recognised corporate firm manufacturing men's underwear, they laugh in disbelief, the ticket checker shrugs it off as a lie. Laal shows them an international magazine with his photo on the cover.

If he is such an internationally recognised business magnate, why is his face so anonymous to the crowd around him? In the second half of the film, we find Laal beginning his famous run, right through the country . He runs from hot summer zones, to snow-capped pathways with crowds gathering in numbers. Yet, the co-passengers in the train do not recognise Laal. This cannot be explained away in an Amir Khan film.

The romantic element is treated with the restraint that the relationship between Rupa and Laal demands. Rupa (Kareena Kapoor) is intelligent yet a failure, but Laal's low IQ leads him to success. He always does just as he is told to by his ammi, or as his mind prompts him to at a critical moment.

Laal's close and intimate rapport with his mother, a brilliant performance by Mona Singh, invests a dynamism to the film not seen in most Bollywood fare which show weepy, weak and depressed mothers. Laal's mother is not only single but exceptionally strong, who defies doctors branding her son physically and mentally weak. She believes that there is nothing wrong with him.

The Kargil war scenes, which are the most outstanding scenes in the film, offer a brilliant insight into the mindset of those caught in the middle of a war. Here Laal is guided by his instinct to save lives. His relationship with Bala who dies at war but his dreams in building a hosiery industry Laal keeps alive, is beautiful.

Ahmed Ibn Umer as the boy Laal looks lovely with beautiful blue eyes but he hardly has a mobile face. He dances with a very young Shahrukh Khan who, we learn, learnt his signature poses from him is a delightful touch.

The other bond is with Mohammed Baaji (Manav Vij) whose life Laal had saved during the war. It may seem melodramatic but works out well thanks to Vij's slow transformation. But every action, every thought, boils down to Laal and his innate goodness underlined again and again by the fact that he takes on life as he thinks fit.

The historical backdrop of Laal's growth from running out of his leg supporting 'traps' to becoming an athlete who keeps running without any intention of breaking records or making it to the newspaper headlines, is crucial. It spans milestones from India's first World Cup Cricket victory in 1983 to the assassination of Prime Minister Indira Gandhi, to the 2008 Mumbai terrorist attacks. But they do not cover much footage and throw up an interesting backstory to Laal's running. Why is he running? What does he hope to achieve? He does not know himself.

Amir Khan, his director, screenwriter and crew have taken great care to tick every box you can imagine. There is communal harmony – Laal is Sikh, Rupa is Christian, his close friend is Muslim; there is regional balance – Bala from the South and Laal from the North; romance between a 'slow' and a normal person; a single mother prepared to work as a housemaid to get the principal to admit her son in his school; the mafia don sexually exploiting Rupa; and the name Rupa for Laal's business borrowed from an already famous brand in men's underwear.

Laal Singh Chaddha is a very entertaining film which should have been stripped of at least 30 minutes of running time. It has an un-hero-like hero, drama, communal friendship, romance, bitterness, death, a beautiful but tragic heroine, lots of songs at every other turn.

But it is Amir Khan's obsession with his own screen image that plays the villain. It is an extremely narcissistic characterisation, and trust Khan to play it to the hilt. There is hardly a frame, except his boyhood days, or, when Rupa is busy being mistress and maid to a mafia lord instead of becoming a leading lady, when Amir Khan is not in the frame. Why?

The cinematography is brilliant and that is an understatement, the camera spans the entire Indian map extremely well, catching the light and the fading sun wonderfully, capturing Laal in his unending run from behind. The editing too passes muster and the song lyrics plus Pritam's music is good too but one feels the film demanded less music and songs.

Amir Khan's performance in the title role is disappointing. He duplicates almost identically, just adding the turban and the long beard, his performance in P.K. Aamir Khan as the wide-eyed Laal, bemused by human life, other than his constant dotting his lines with "Hmm" hardly contributes much more than the "eyebrows-glued-to-the-forehead" look. This is a classic example of a very talented star-actor falling victim to his own Narcissism. Sad.

The film opens with a white feather landing on Laal's shoes. He picks it up and tucks it carefully into his bag. The final scene shows a white feather floating away against an azure blue sky. Why? If only Amir Khan had not fallen head over heels in love with his own screen image!