Recalling the story behind the catch-phrase, Aditya told PTI, "I had some friends from Defence background, so with them I used to go to a lot of Army clubs. There was one in Delhi where we used to go for Christmas or New Year parties. There used to be a retired Brigadier who would line up all the kids in front of him and have a chocolate in his hand.
"He would say 'How's the josh?' and we were to respond with 'high sir!' The kid who was the loudest got the chocolate. Being a foodie, I used to be the loudest and always got the chocolate," Aditya told PTI.
The phrase has acquired a life of its own, something that the director had never anticipated.
'Uri' actor Vicky Kaushal on 'How's the Josh': It's not a dialogue, it's an emotion
"I have heard very few Army people use the phrase. It is not something which is used extensively. What I did was I used the line in the right way in the film and now it has taken off to another level."
When Aditya sat down to pen "Uri: The Surgical Strike", he knew he had to include the line.
"The line was there right from the first draft. As a writer, we write according to our personal experiences, our memories. It is an amalgamation of everything. I had the line with me in my memory and this was the perfect film for it to come out."
The film, which released on January 11, has emerged as a huge blockbuster, still running to packed houses and all set to enter the Rs 200-crore club.
For the first-time filmmaker, Aditya says the response has been "magical, beautiful" and the magnitude of love coming the film's way was something the team never anticipated.
The film's journey-and it's eventual success-is stuff of legends for Aditya.
The director was working on "Raat Baaki", which was supposed to feature Pakistani actor Fawad Khan and Katrina Kaif in the lead but Khan had to exit the project after Pakistani artistes were banned from working in India in the aftermath of the Uri attacks.
Aditya turned the situation on its head and made a different film, which has not only been a box office success but also taught him to use unpredictable nature of the business in his favour.
"I learnt in this industry that whatever the adversity, you have to just push yourself and change the situation in your favour. When the surgical strikes happened and Pakistani artistes were banned, everyone was sad that our film won't get made.
"I wanted to know what happened during the attacks because that sounded like a great story. That switch happened very fast. It is the only way to survive in this industry, it is difficult, you have to be mentally strong. No matter what, you've to always keep the josh high," he said.