London, England (CNN) -- They might have been trained to ride flying broomsticks and mix potions but life after Hogwarts is still a riddle for the young magicians of the Harry Potter series.
With filming in the last part of the series --"Harry Potter and the Deathly Hallows: Part II" -- well underway, the cast of the multi-million selling franchise seem bound to look back and reflect on their nine-year-long magic ride.
"It was September 29, 2000," Daniel Radcliffe, now 20, told CNN with a hint of nostalgia about his first day on set in Goathland railway station in northern England.
"Me, Emma [Watson], and Rupert [Grint] had all traveled up that day in a minibus, and we sat on the back seat -- which was undoubtedly my influence -- pretending that we were DJs on a radio station."
Surely, not many of those present at that first shoot could have predicted Harry Potter's unprecedented level of success in the coming years.
The film series, whose sixth installment "Harry Potter and the Half-Blood Prince" was released on DVD and Blu-Ray on December 8, has become the most successful franchise in history, smashing several box office records and amassing billions in revenue.
The first six Harry Potter films have grossed $5.4 billion according to the Guinness Book of Records, making it the most successful film franchise ever.
The figure is expected to rocket still higher when the seventh chapter hits cinemas in November 2010, followed by the eighth and final installment in the summer of 2011.
After initially beating more than 40,000 young hopefuls to their roles, the series' wide-eyed stars have spent nearly half their life casting spells at Leavesden Studios outside London, where the Harry Potter sets are housed.
"I'll never forget walking through those amazing doors for the first time, as we have done many a time since," Tom Felton, who plays Harry Potter baddie Draco Malfoy, told CNN.
"I also remember auditioning here. The crazy thing about the audition was that, at my very first audition -- when they had thousands of kids in, day in day out -- Emma Watson was standing next to me and we did it together. And I came back in two weeks and she had been cast!"
Looking ahead to the future, you don't have to be a wizard to guess that sentiments will run high on the Potter set when director David Yates shouts "cut" for the last time.
"It will be very, very sad to think that I can't come here every day and work with my best friends all the time. I spend 90 percent of my time here laughing every day and it's wonderful," said Radcliffe.
Shooting on "Harry Potter and the Deathly Hallows: Part II" is expected to finish in May 2010. It will mark a momentous change of chapter in the life of the saga's young stars.
"Before this film you never really thought about it ending, you kind of just thought it was going to go on for ever. It's going to be quite a moment I think because my whole childhood is really in this place," said 21-year-old Rupert Grint, who has spent the last decade playing Harry Potter's loyal friend Ron Weasley.
But Grint quickly goes to stress that he is ready to leave Hogwarts' gates behind him and move on to new ventures -- this time without the help of magic potions. "I think I'm ready to move on and get out into the real world and see what it's like," he told CNN.
All the young stars seem excited about what the future holds for them, helped by the fact that they have roles in the world's biggest movie franchise under their belts.
"It will be very exciting to not have to say, 'Sorry I'm not available for the next three years, can you wait?' if a fantastic script comes in," said Radcliffe who has used his breaks from playing Harry to take part in projects on Broadway and West End.
The end of the Harry Potter series is surely not the end of the road for the saga's global stars, although they admit they may not have dry eyes as they leave set for the last time.
"Tears will be shed, I'm sure," said Felton. "Tears of joy and tears of leaving it all behind as well. I know we're all very excited to see what's going to happen afterwards and where we'll all going to go.
"But saying that, I think most of us right now are just trying to appreciate the time we have left."