Queen Elizabeth II is known for her great sense of humor. She sometimes also manages to walk among a crowd without being recognized. The most apt example of this was when she was approached by a group of American tourists while out on a walk near her Balmoral estate in Aberdeenshire.

Ahead of the British monarch’s 90th birthday on Thursday, her former protection officer Richard Griffin shared snippets from her life. The now 89-year-old royal was dressed in a head scarf and a tweed coat. She was asked by American tourists if she lived in the area, to which she responded by simply saying she had a house “close by.”

Griffin, who worked closely with the monarch for more than 30 years, was speaking to The Times. He said the group then moved on, not realizing that the person whom they had just met and spoken to was none other than Queen Elizabeth herself. “Have you even met the Queen?” the group then asked, to which she replied, “No.”

However, Elizabeth pointed to her companion and said that he had seen the queen. Besides, a few days earlier, warrant officer John Ross revealed that the queen was in the habit of checking the quality of her soldiers’ packed lunches to make sure they were “being looked after properly.”

“The royal family were so much fun to work for, they made all the soldiers feel at ease,” said the 61-year-old who served for 25 years in the King’s Own Scottish Borders regiment, helping to protect the royals on their visits to Balmoral.

He added that it was a priority for Elizabeth to look after the welfare of her soldiers as the latter were responsible for providing support for all events. Ross said that she would come into the kitchen and check their packed lunches before they went on hunting or fishing trips. Elizabeth would inspect the sandwiches and if they were not up to the mark, she would send them back, he told the Telegraph.

As a 5-year-old, Lilibet, as she was fondly called had written a letter to her grandmother Queen Mary. The letter was first made public ten years ago, when Elizabeth celebrated her 80th birthday.