The pop star-turned-fashion designer made the revelation in a letter to her future self, which she penned for British Vogue.
In it, she describes the “life-changing” night she watched Elton perform at a gig in Las Vegas, that led to her moving on from the most successful girl group of all time.
She writes: “Remember years ago, watching your dear friend Elton John on stage in Las Vegas. He performed Tiny Dancer, as if it were the first time, and you realised this was like oxygen for him.
“It was a life-changing moment — while singing and dancing was fun for you, it wasn’t your passion.
“That day, you started your quest to uncover your own dreams. It was time to step away from being a Spice Girl.”
After making the decision not to continue with the girl group, Victoria, AKA Posh Spice, went on to put her name to a hugely successful fashion and beauty brand, which she admits was “terrifying”.
“For the first time, you were venturing out on your own, and it was terrifying. It was scary to close a chapter that defined you,” she writes.
“I know you are still reinventing yourself, taking on new challenges, and ignoring the naysayers. You always look beyond the conventional wisdom to pave your own path.”
Victoria added that she “always liked to surprise people – especially [husband] David”.
“Preserving that bit of mystique is always helpful after almost 22 years of marriage,” she says.