Prince William joked about his "Harry Potter scar" as he recalled a childhood accident during today's outing.
The Prince of Wales referred to his head wound as he met with businesses and organisations which promote the benefits of seaweed.
During a visit to Cardiff Metropolitan University, he told entrepreneurs how he got the injury after being hit with a golf club as a child.
Pointing to a mark above his left eye, William also admitted he has never played the sport since.
The prince chatted to Pierre Paslier, co-founder and co-chief executive officer of Notpla, a former category winner in William's Earthshot environmental prize.
Notpla supplies seaweed packaging to major UK sports and music venues.
William was asked if he enjoys playing golf as he picked up a biodegradable tee made from marine algae.
He replied: "No, (this happened) the last time I played golf."
William pointed to the scar which he gained in 1991, aged eight, when he was accidentally struck with a friend's club during his time at a boarding school in Berkshire.
The prince was taken to the Royal Berkshire Hospital in Reading for treatment.
He was left with a scar similar to the title character of JK Rowling's bestselling book series, Harry Potter.
William spoke about his injury 18 years later, during a chat with a 10-year-old cancer patient for BBC's Newsround.
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He said: "I got hit by a golf club when I was playing golf with a friend of mine.
"We were on a putting green and the next thing you know there was a seven-iron and it came out of nowhere and it hit me in the head."
William went on to explain that his scar sometimes "glows" like Harry Potter's famous lightning bolt scar.
"It glows sometimes and some people notice it - other times they don't notice it at all," the prince quipped.
