Meghan Markle just celebrated her birthday this past Sunday, presumably with her husband, Prince Harry, and baby boy Archie Harrison by her side, but believe it or not; birthdays weren't always like this for the Duchess of Sussex. In fact, the now 38-year-old experienced the "scariest moment in her life" when she was 21.

Royal biographer Andrew Morton took readers through the "terrifying ordeal" in his book "Meghan: A Hollywood Princess."

As a student at Northwestern, Meghan interned for the U.S. State Department in the Argentinian capital of Buenos Aires as a junior press officer and as a "treat" for working on her 21st birthday, "she was given permission to travel in the convoy that was picking up the US Finance Secretary Paul O’Neill," Morton wrote, according to Express.

Unfortunately, what should have been a highlight of Meghan's college career turned scary due to an announcement the Finance Secretary made before his flight.

"Argentina had recently defaulted on a $141billion debt and neither the International Monetary Fund nor the American government were in any mood to bail them out. Before he left Washington, O’Neill had announced that South American nations should have policies in place to ‘ensure that aid is not diverted to Swiss bank accounts,’" Morton explained. This upset some locals, and it showed it when he landed.

The author wrote that "banner-waving demonstrators surrounded the convoy," and O'Neill shared that "protesters banged on my limo," the same vehicle the future Duchess was also riding in.

Morton continued to explain that Meghan, "was terrified, recalling that it was the scariest moment in her life."

Thankfully, the mother of one can leave that experience in the past. She's got much more pleasant matters to attend to, like who to invite to her birthday party.

Meghan Markle
Meghan Markle, the Duchess of Sussex is pictured attending a panel discussion convened by the Queen’s Commonwealth Trust on March 8, 2019 in London. Daniel Leal-Olivas - WPA Pool/Getty Images