The 61 year old was propelled to stardom after her turn in 1978 movie Grease and graced the covers of magazines worldwide.
Newton-John refused to take her pin-up status seriously at the time, and claims the decision kept her grounded.
But the actress feels sorry for Spears, who found fame as a teenager in the late 1990s – because the amount of press coverage sexy stars receive nowadays is unprecedented.
She tells Britain’s Attitude magazine, “The poor girl. She has lived in a time where the paparazzi reign and we didn’t have that problem at all. We’d have occasional intrusion, you know I had a few incidents, but it was nothing like it is now.
“I don’t think you realise it (early fame) until you look back because it doesn’t really feel like reality in the time. I never really took it too seriously, which is healthy.”