Nearly fifty years ago, a fresh-faced young actor named Amitabh Bachchan traveled to Mumbai, the so-called "City of Dreams," to find work.
Since then, he has starred in more than 200 films and is now considered by many the "undisputed Godfather of Bollywood."
Bollywood — a portmanteau created from Bombay (as Mumbai was formerly called) and Hollywood — is the nickname for the Hindi film industry centered around the city.
It contributes nearly half of the total box office revenue in India, according to a 2016 Deloitte report, and has picked up a sizable international audience over the years. One of Bollywood's recent films, "Dangal," has raked in nearly $300 million at the box office, with a majority of it coming from outside India. That is an Indian film industry record.
Much as is the case in Los Angeles, breaking into Bollywood is not easy. But that doesn't stop thousands of aspiring actors from all over India from turning up in Mumbai every year to try to make it on the big screen. Mumbai has a population of at least 18 million, according to 2011 census data, making it one of the more densely populated cities in the world.
"There's so much happening here, there are so many opportunities for people that live in smaller towns," Bachchan told CNBC's "Trailblazers" about Mumbai. "It's been said that if you come to this city, you won't spend a night without a meal or you won't be hungry … there's always something to do, some job to do where you can survive."
Bachchan was born in the city of Allahabad in the northern state of Uttar Pradesh. He completed his college education in Delhi, and spent seven years working in Kolkata before making his trek to Mumbai. It was by chance that at the same time that Bachchan was about to arrive in Mumbai, a film producer was looking to cast new faces for a project.
"I was coming in search of joining the movies, but had actually made some initial ground," Bachchan said. "Because there was the producer of the first film that I did, who was looking for fresh faces."
Bachchan's brother, at that time living in the city, was the one who first learned about the producer. Bachchan said his brother "pushed my photograph to the gentleman, and he seemed to want to meet me. And so I was arriving for that, and fortunately the day I arrived I got the job, my first job."
Bachchan made his film debut in 1969 as a voice narrator in the award-winning film "Bhuvan Shome," the story of an uncompromising widower working for the Indian Railways. He also got his first acting gig that same year in the film "Saat Hindustani," where he played a poet named Anwar Ali, from the state of Bihar, who joins up with other protagonists to spread Indian nationalist sentiments in Portuguese-occupied Goa.
Beyond the quick success of landing his first paid gig, Bachchan said it was back to "going from door to door and looking for a job" that was fundamental in building his expansive career. According to him, being persistent is important in breaking down the doors of the film industry. For him, it was routine to "get up in the morning and go and visit studios" in order to "try and sell your face to them."
Bachchan spent the next few years making about a dozen films before he landed his breakout role. In 1973, he starred as police inspector Vijay Khanna in the film "Zanjeer," where his brooding lead character is an honest cop in a crooked town.
Bachchan said he wasn't sure what made the writers of "Zanjeer," Salim Khan and Javed Akhtar, and the director, Prakash Mehra, see him as a suitable candidate for the lead role.
"I have never wanted to know what it was that they saw in me which gave them the decision that, you know, I should be working on this film," he said. According to him, the writers and the director told Bachchan they had seen some of his action work in an earlier film that convinced them he was right for the role.
"There was an action sequence in a restaurant, where I was there for a cup of coffee, or having a sandwich, and I had to fight somebody and he came up and punched me … and I took a couple of somersaults on the floor and I got up," he said, of the scene from the previous film.
"And I was still chewing my sandwich and that, they felt, was the reason why they chose me for the film Zanjeer, which is rather odd, but that's what they told me."
These days Bachchan, 74, is still making films, as well as doing some work on television.
Last year, he appeared in four films, including the critically acclaimed courtroom drama "Pink." In the film, he plays an aging lawyer, Deepak Sehgal, who defends three young women against a group of influential men who tried to sexually assault them. The role earned Bachchan several nominations for best actor, and he won three of them, including a critics choice award.
He is also active on social media, where he writes a regular blog and has both a Facebook page and a Twitter feed. The blog allows him to interact directly with fans.
"If somebody has reacted to my blog, and said something, then I have the facility to be able to react to his reactions as well," he said. "And it's been a wonderful experience."
—CNBC's Lucy Handley contributed to this report