He arrived at Friday's Canada Day celebrations heralded as the country's future king, yet when thousands of Canadians erupted into cheers in front of Prince William and his new wife Catherine, the rookie royals didn't seem to know exactly what to do.
They smiled, sometimes sheepishly - and the cheers grew louder. Whenever Kate waved, it seemed her adoring fans would burst with joy. It took Prime Minister Stephen Harper to calm the crowd down - at least until he mentioned the couple by name once more.
Even fans were at a loss to explain their affections.
"I just love them," gushed Kirsten Bourke, 23, from Nova Scotia. "I don't know why."
Friday was a full-on, no-holds-barred display of puppy love for the newlyweds, an infatuation with a couple of starry-eyed kids from England, that Buckingham Palace is keen to see transformed into a lasting relationship with the Commonwealth.
The nine-day tour of Canada by the Duke and Duchess of Cambridge, their first official trip as a married couple, is being analysed right down to the feathers on Catherine's fascinators to see if they have the mettle for the rigours of royalty.
Prince William's grandmother, "the Queen of Canada," is watching closely, he acknowledged in his Canada Day remarks.
"The Queen has taken a great interest in the themes and program of our tour, and looks forward to following our progress as it unfolds," Prince William said in a speech peppered with textbook French.
She has warm, abiding memories of her own visit last year, he added, before describing Catherine's own interest in Canada, her pilot grandfather having trained in Alberta. The couple's itinerary, which includes Quebec, P.E.I. and the Northwest Territories, ends next week in Calgary.
"Catherine and I are also thrilled and excited at the prospect of the next eight days, especially being part of the Canadian family," Prince William said.
"It will be an adventure that we'll never forget."
Family was also on the minds of royal watchers on Friday, which would have been the 50th birthday of William's mother, the late Diana, Princess of Wales, who was killed in a tragic car accident in August 1997.
"Happy birthday, Diana," several people shouted as Prince William and Catherine made their way up to Parliament Hill.
"I think she would been very proud of him," said Mary McAllister, 53, of Toronto, as she watched the couple work the crowds via a massive television screen set up in the middle of a downtown street.
"He is so like her. He looks so like her."
But where Princess Diana had a habit of outshining Prince William's father, Prince Charles, this royal duo seems determined to make their coming-out a tandem effort, even if they do work the crowds in their own distinct and separate ways.
"They are graceful, they are majestic. They really represent highness, let's put it this way," said a 55-year-old man named Jean, who declined to give his last name.
As they make their way through the throngs, each royal makes eye contact and engages, if only for a moment, with each person they meet. She lingers longer in the crowds, often turning to discover the rest of the party waiting for her up ahead. Sometimes they call out to one another to introduce a particular person, or - in Catherine's case - to take another bouquet of flowers.
Prince William drew laughs Friday when he quickly donned a proffered pair of sunglasses to shield his eyes from the harsh midday sun.
Before the early-afternoon festivities had even started, some spectators who had been holding their spots for hours prior to the event succumbed to the blistering Ottawa heat. At least one person was taken away on a wheeled stretcher.
Greg Kolz, of Ottawa, spent the night in his spot on the Hill, a tactic that proved well worth it when he got the chance to speak briefly with Prince William when the day's festivities were over. The fact he briefly succumbed to the heat and fatigue didn't much matter.
"The only unfortunate blemish on my record, I suppose, is that I accidentally wished the prince a Merry Christmas, to which he said that's happened to him," Mr. Kolz said.
"And that was brilliant."
Earlier in the day, cannon fire and the scream of Canadian fighter jets heralded their arrival via landau on Parliament Hill as the estimated 300,000 people welcomed the Duke and Duchess of Cambridge to Canada's birthday party.