For many in Generation Z, their first understanding of the September 11th attacks did not come on the day itself, but years later, through fragmented memories of school lessons, family stories, and independent internet searches. These individuals, born in the late 1990s and early 2000s, often recall learning about the "deeply harrowing, terrifying" events in elementary school, with details like the "falling man" image or President George W. Bush's reaction at an elementary school event sticking with them.

Avery Black, 20, remembered asking her mother about 9/11 after a school lesson. Her mother, recalling the day, described the loss of firefighters and broke down in tears. "She just started telling me where she was the day it happened, and just broke down in tears, explaining to me about all the firefighters that went in and never came out," Black told the BBC.

Annie Erickson, 26, found her initial memories shaped by personal connections. Her mother, who grew up in New York City, shared that a friend from her building had died in the towers. Erickson noted that teachers were often able to personalize the historical event with their own memories, making it more impactful.

Allegra Tashjian, now a 28-year-old PhD student, recalled a more detached introduction in first or second grade. When a classmate mentioned planes hitting the towers, Tashjian realized she had never heard of it. Later, at home, her mother seemed hesitant to discuss the topic, saying she didn't remember anything about it.

For many, including Tashjian, Black, and Erickson, a deeper comprehension of the attacks only came through later personal research. "I really understood the gravity of it more from reading things on the internet when I was probably between like nine and 12," Tashjian said. Black added that she didn't initially realize it was a terrorist attack, a detail she learned through her own research, finding it difficult to explain the concept of a terrorist to a child.

This delayed understanding is partly due to varying educational requirements across the United States. Currently, there is no national mandate for schools to teach about the 9/11 attacks. A recent analysis by The Associated Press found that 25 states require or encourage public schools to teach the events, while 13 states make it optional, and not all states that require instruction specify a curriculum.

Despite the passage of time, interest in the events remains. Professor David Schanzer, who teaches a course on "9/11 & Its Aftermath" at Duke University, noted that his class is consistently full with a long waitlist. He observed that current global events seem to fuel younger generations' curiosity about the 21st century's "first global catastrophe," as he described it, drawing parallels to the Great Recession and the COVID-19 pandemic as other significant global events.