The Candy hitmaker reaches the milestone age of 40 in 2014 and thinks that will mark a point where his career is viewed in a different light.
"I'm 40 soon so I've got two years left of being a pop star and then I become an old man on stage singing," Robbie said.
Robbie, who became a father to daughter Theodora "Teddy" Rose in September, also admitted he had turned to the gym as he panicked about his physique ahead of promoting his new album Take the Crown when he began piling on weight after quitting smoking, though he now thinks he has gone too far.
Teddy's first Christmas
Speaking on stage at the Marmite Christmas Lights switch on in London's Oxford Street, he said: "I went from smoking three packs a day to none, and I put on some weight and knew I wasn't going to be able to lose it in time to promote the album.
"So I just started pushing weights and now I look like a doorman."
While Robbie and wife Ayda Field are looking forward to their first Christmas with Teddy, he won't be buying her any gifts.
"It's Teddy's first Christmas, so that's going to be really special. But she's too young to remember anything, so she won't be getting any presents," he admitted.
24.com publishes all comments posted on articles provided that they adhere to our Comments Policy. Should you wish to report a comment for editorial review, please do so by clicking the 'Report Comment' button to the right of each comment.
Country legend Kenny Rogers tells us about his feelings for South Africa, his farewell tour and his friendship with Dolly Parton. Read More »
South African TV and music insiders are all pointing to Trevor Noah as the perfect frontrunner to host. Read More »
South AfricaHomeMarkR15 000 - R20 000 Per Month
South AfricaHomeMarkR11 000 - R15 000 Per Month
HousesR 3 200 000
HousesR 11 000 000
HousesR 1 650 000