The duchess, now a potential future queen as wife of Prince William, was a student at St. Andrew's School in Pangbourne, Berkshire, from the age of 4 to 13. She went on to Marlborough College and then to St. Andrew's University in Scotland where she met William.
She visited the school Friday, St. Andrew's Day, wearing a tartan coat dress in honor of Scotland's patron saint, The Daily Telegraph reported.
"I absolutely loved my time here, they were some of my happiest years, which makes it so incredibly special to be here today," she said. "In fact, I enjoyed it so much that when I had to leave, I told my mother that I was going to come back to be a teacher."
The duchess opened a new Astroturf playing field, named in honor of Queen Elizabeth II's Jubilee year. Her husband did not accompany her on the visit.
During time with the school's youngest students, she said that she and her sister, Pippa Middleton, were nicknamed Pip and Squeak. They also gave the names to their guinea pigs.
At school, the duchess was a sports enthusiast, participating in swimming and track, where one of her school records still stands, and serving as captain of the hockey team. She also excelled in music and acted in plays.
The duchess first saw Prince William while she was at St. Andrew's, the Telegraph said. He attended Ludgrove, another Berkshire prep school, and came to St. Andrew's for a hockey game.