Queen Elizabeth II is remarkably and unabashedly particular: For example, she's never wavered from the corgi breed when selecting the no less than 30 dogs she's owned during her reign, and has made a point to eat the same food—a slice of chocolate biscuit cake—every single day. (Yes, even while traveling.)

It's no surprise, then, that now that she's 91 and definitely put in her time observing decorum, upon being given the occasion to reflect on her coronation 65 years ago, the Queen is sharing her real two cents on what was a "pretty challenging day for her as a 25-year-old," as the royal family reporter Alastair Bruce described it to InStyle. That much was clear after he was with the Queen when she watched her coronation for the very first time, as part of the upcoming documentary The Coronation, which examines the 1953 ceremony on its 65th anniversary.

After 14 months of preparation, which included the soon-to-be Queen disagreeing with Prime Minister Winston Churchill and deciding to make hers the first coronation ever televised—as well as the first major event televised around the world—the big day rolled around, beginning with the Queen parading around London, making what was at least a five-mile trek from Buckingham Palace to Westminster Abbey with an out-of-the-way stop at Trafalgar Square.

The official voyage took place via an enormous gilded carriage—a much more regal-sounding upgrade from the arrangement of chairs that had been the stand-in in rehearsal, but which actually turned out to be much to the Queen's displeasure. She may have kept quiet at the time, but now, 65 years later, the Queen apparently had no qualms about describing the ride as "horrible." (In case you don't feel like watching the whole hour-and-18-minute ordeal, you can get a glimpse at the carriage in the video below at 15:30.)

"It’s only sprung on leather, not very comfortable," she recalled of the carriage. "We could only go at a walking pace. The horses couldn't possibly go any faster. It's so heavy."

The Queen got more practice with wearing the enormous Imperial State Crown, which weighs five pounds and was originally designed for King Charles II, and made of solid gold all the way back in 1661. It was not only too big for the Queen, but also much too heavy along with the rest of the regalia, which is why she wisely practiced wearing it ahead of time by donning it while going about her ordinary day, such as while reading the newspaper or taking her tea.

Not even that, though, was sufficient to prepare her for its weight on the day of the coronation: "There are some disadvantages to crowns, but otherwise they're quite important things," she said, elaborating that she learned on coronation day that "you can't look down to read the speech, you have to take the speech up. Because if you did, your neck would break and [the crown] would fall off."

Queen Elizabeth II and Prince Philip after the coronation, June 1953.

After such an ordeal, here's hoping she made an exception and deigned to reward herself with at least two slices of chocolate biscuit cake.

Related: Princess Margaret's Morning Routine Proves She Was Really a Queen