cnn

London, England (CNN) -- The thing that struck Charles Warren about Prince William, second-in-line to the British throne, when he first met him was how "regular" he was.
"William, in almost every regard, was just a regular student," says Warren, a geography lecturer at the University of St. Andrews and William's tutor from 2001 to 2004.
"William has always struck me as a very personable, level-headed young man, which is very remarkable, given the background he's had," he added.
Warren was among a small group of students and teachers, including William, who went on a geography field trip to a remote part of Norway in June 2004.
"We were at the end of a very long dead-end road in the middle of absolutely nowhere," remembered Warren. "Tiny community in a campsite, completely away from the world's media."
"You could tell he was completely relaxed," he added. "He was completely himself. He let his hair down.