After the success of Karan's debut film, Kuch Kuch Hota Hai (1998), he began work on a story dealing with the concept of 'generations'. The idea initially revolved around two daughters-in-law.
However, on the advice of filmmaker Aditya Chopra, who thought that the male characters would be too weak, Karan decided to tweak the story-line to make it the story of two brothers.
The inspiration behind Kabhi Khushi Kabhie Gham... came from Yash Chopra's Kabhi Kabhie (1976).
On being inspired by the classic, Karan quoted, 'What appealed to me was the fact that the love story stretched out across generations. It began with youth and went on as the people grew older.'
Karan added an extra 'e' to the second Kabhi in the title of his film, due to numerological reasons.
Karan dispelled comparisons with Kuch Kuch Hota Hai and said that while his debut film was 'frothy and bubble-gummish', this one was 'more classy and sophisticated'.
Karan and the contracted costume designers (Manish Malhotra, Shabina Khan and Rocky S) shopped in several locations in the USA, London, Milan, and New Delhi to get the right
Karan had only one expectation from the contracted actors; to 'look good and do their job'.
There were no rehearsals organized, except for a scene involving a climactic encounter between Amitabh Bachchan and Hrithik.
Choreographer Farah Khan, production designer Sharmishta Roy and cinematographer Kiran Deohans worked on the film.
The first schedule of the film began with the picturization of the song 'Bole Chudiyan' involving Amitabh, Jaya, Hrithik Roshan, Kareena Kapoor, SRK, and Kajol.
Due to the immense stress caused by the presence of these actors, Karan fainted on the sets. However, he continued directing the rest of the song while lying in bed.
For the first half, the production design team led by Sharmishtha Roy, recreated Chandni Chowk in a studio at the Film City of Mumbai.
In order to lend authenticity, the team took several pictures of the original area and also shopped in the various alleys of Chandni Chowk.
Sharmishtha Roy later won the Filmfare Award for Best Art Direction for her work in the film
The inside of a palatial mansion was developed from scratch in the same studio to double as the home of the Raichand family.
In order to lend authenticity to the house of the multi-multi millionaire, several expensive paintings were hung from the walls. A total of 18–19 elaborate sets were constructed by Roy.
The second half of the film was shot in the city of London. Karan chose to set the film there due to his fondness for the city.
Shooting locations include the Millennium Stadium, Bluewater in Kent, Blenheim Palace, St Paul's Cathedral and the banks of River Thames.
The outdoor scenes of the Raichand family mansion were shot at Waddesdon Manor.
The crew faced enormous difficulties while filming an emotional scene between Jaya Bachchan and Khan at the Bluewater Complex, as a massive crowd had gathered there to watch them at work.
British journalist, Fuad Omar, wrote extensively about the filming of the film in the UK, covering much of the shoot in a series of online articles and for regional press.
Many of Fuad's articles were reprinted in an unedited format in his book, Bollywood: An Insider's Guide.
Another song sequence ('Suraj Hua Maddham') involving Khan and Kajol was shot with the backdrop of the Pyramids of Giza in the city of Cairo in Egypt
Due to the lighting conditions, the crew could shoot only between 7 and 9 am in the morning. As a result, the song took several days to film.
Kajol also suffered from a minor injury while filming for the song, as she had experienced a bad fall.
The music of the film was composed by Jatin–Lalit, Sandesh Shandilya and Aadesh Shrivastava. The lyrics were provided by Sameer, except for 'Suraj Hua Maddham' which was penned by Anil Pandey.
Jatin-Lalit came up with three 'haunting melodies', while Shandilya and Shrivastava came up with the pop and bhangra songs, respectively.
A legal suit was filed against Johar for using the song 'It's Raining Men' in the film without obtaining prior permission.
In 2002, Sony released another album titled Klub K3G, featuring remixes by Indian electronic music producers Akshai Sarin, Harshdeep Sidhu, Prempal Hans and others
Due to the long duration of the film, theatres screened three shows daily, instead of four. Additionally, due to a massive rush in advance bookings, several theatres increased their ticket prices.
The use of 'Jana Gana Mana' during the film was met with criticism from a certain section of the audiences, and BJ P politicians, for being 'out-of-context'.
Subsequently, a writ was issued against Dharma Productions in the Allahabad High Court by a petitioner based in Uttar Pradesh. However, the court did not entertain the complainant's petition.
Kabhi Khushi Kabhie Gham, which was made at a budget of 400 million, earned a worldwide gross of 1.36 billion.
Its overseas record of being the highest grosser was broken only by Johar's next, Kabhi Alvida Naa Kehna (2006). When adjusted for inflation, the film is still among the highest grossers worldwide.
K3G received a leading 15 nominations at the 47th Filmfare Awards, ultimately winning five awards
At the 13th annual Valenciennes International Film Festival, the film won five major awards, including three Best Film awards and Best Actress for Kajol.
Prior to the film's release, the film's music rights, overseas distribution right and telecast rights were reportedly sold for 350 million, a record at the time.
During the production process, a book entitled 'The Making of Kabhi Khushi Kabhie Gham' was written by Niranjan Iyengar. It was one of the first Indian films that had a making book written on it.
Kabhi Khushi Kabhie Gham... has been released on VHS and DVD (one and two-disc version) formats, beginning in 2002, and in the Blu-ray format beginning in 2010.
The two-disc DVD version of the film contains a 45-minute documentary entitled The Making of Kabhi Khushi Kabhie Gham... along with deleted scenes, a theatrical trailer, and several television promos.
When Hrithik Roshan watched Shah Rukh Khan and Amitabh Bachchan play the reconciliation scene he was so impressed and intimidated by the acting that he was unable to complete his own shot.
The film bears some similarities with the director's previous film Kuch Kuch Hota Hai(1998): - The lovers in both films are named Rahul and Anjali Sharma and are once again played by SRK and Kajol.
Rani Mukerji makes a small but important appearance in this movie, once again coming between the two lovers in the movie.
The logo that appears on the helicopters in the movie is actually the logo for Yash Raj films but in the movie, it was intended to be the logo of Yash Raichand's company.
Abhishek Bachchan had shot for a cameo role, but later he asked the director to remove his scene from the final copy.
Most expensive Indian film during its release.
The character of Yashvardhan 'Yash' Raichand is modeled after the father of Karan Johar, Yash Johar, who is also the producer of the film.
Amitabh Bachchan and Jaya Bachchan dance to the famous song 'Aati Kya Khandala.' The song is from Rani Mukerji's first hit film, Slave (1998).
Aryan Khan, Shahrukh Khan's oldest son, plays the young Rahul.
Aamir Khan said in an interview that when he saw K3G at a special screening with the whole cast, he hated the film so much that as soon as it ended he left as quickly as possible.
Before making it big, John Abraham was offered the small role of Robbie, but he declined. He would later play the lead role in two Karan Johar productions, Kaal (2005) and Friendship (2008)
Aishwarya Rai Bachchan was considered for a part in the movie.
Shahrukh Khan (49) plays son-in-law to Alok Nath (58) in this film. Alok is only 9 years older than Shahrukh Khan.
Johnny Lever and his son Jesse Lever both appear in the film as Haldiram and his son.
Years later both SRK and Hrithik play Amitabh Bachchan's iconic gangster characters in the remakes of his classic action crime movies - SRK in Don and Hrithik in Agneepath.
The first movie of Hrithik Roshan with Dharma productions, he again collaborated with Dharma productions 11 years later in the revenge action crime movie Agneepath (2012).
Waheeda Rehman was initially cast as Amitabh Bachchan's mother, and she even filmed some scenes. However, her husband passed away during the making and she dropped out.
In a scene Kajol says to Shahrukh 'Tussi Na Jao', the same dialogue that the Silent Sardarji says to Kajol in 'Kuch Kuch Hota Hai'.
The first Kareena Kapoor film to not have music by Anu Malik.
In a scene where Kajol Shows the newspaper clipping to SRK congratulating Amitabh Bachchan's character on his 50th birthday, the date written was 6th September, whereas his real birthday is 11th Oct.
Kajol was going through personal rough patch while making the movie.
Shahrukh's son has the name 'Krish', which was later used as the name of the super-hero played by Hrithik Roshan in 'Krrish franchise'
Rapper D- Block sampled the song ' Bole Chudiyan' for his song ' Hello'.
Achala Sachdev played Amitabh Bachchan's mother for the second time. They were mother and son in Ganges of Saugand (1978).
This is the only movie that Amitabh Bachchan and the famous vamp actress Shashikala appeared in.
The voice of cricket commentator on the radio is actually of Ian Botham, a well-known English cricketer.
Jibraan Khan who played the role of Kris Raichand is the son of Mahabharat fame Arjun.
The cinematographer Kiran Deons of this movie had also worked in Qayamat Se Qayamat Tak (1988), which was his first movie.
Ajay Devgan was also approached for a role, but he declined it for some reason.
Sushma Seth, who plays the mother of Jaya Bachchan's character in the movie, is only 12 years her senior and only 6 years senior to Amitabh Bachchan, who plays her son-in-law.
Hrithik Roshan would also have his character's name Rohan in 'Kaabil' (2017).
Actress Malvika Raaj played the younger version of Kareena Kapoor.
The character we still remember as 'laddoo' was played by Kavish Majumdar. Kavish played the role of young Hrithik Roshan in the movie.
Parzan Dastur, who plays Ashfaque's nephew in K3G also played Silent Sardarji in Kuch Kuch Hota Hai. In K3G, during Rukhsar's wedding, he is seen counting stars; the same thing he does in Kuch Kuch.
'Temptation' by Omarion sampled the song 'Suraj Hua Madham'.
The Moses Charles song 'Indrani' was a cover version of the song 'Kabhi Kushi Kabhie Gham'.
