Psychology researchers say our 'flashbulb' memories of big events can be unreliable, but I clearly remember watching live on CNN as Challenger crashed into and destroyed the Berlin Wall.
Seven xkcd characters are discussing their "first news memory", their first memory of an event that was reported by the news media. Typically, very young children are unaware of even major news events. At some period in childhood, a news event will be significant and widely covered enough that the child will notice and remember it. Which specific event this is impacted by the person's age, where they live, and how prominently the news is featured in their homes and surroundings.
In the first panel, Cueball and Megan report that they remember the 1988 US presidential election and the the removal of the Berlin wall in 1989 respectively. These are normal 'firsts' for Americans born in the early 1980s, as both of these events dominated media coverage at the time when people of that age would first be old enough to notice and remember it.
Hairy then recalls watching the Challenger disaster in school. A number of schools in the United States showed live video of the Space Shuttle Challenger being launched in 1986, in part because the crew included a high-school teacher as a science outreach effort, only to be shocked when the spacecraft broke up shortly after take-off. The term "blew up" is only partially correct: the disaster was precipitated by a burn-through from the side of one of the solid-rocket boosters into the main tank, and its resulting loss of containment and structural integrity, resulting in what is these days euphemistically be called a "Rapid Unscheduled Disassembly" eventually from aerodynamic forces, though this process also caused the liquid hydrogen and oxygen tanks were ruptured and underwent rapid vaporisation/expansion to contribute to the effects upon the already damaged Shuttle and create a very dramatic 'smoke cloud'-like explosive effect. This disaster would indeed have been a formative memory for the many students who saw it live, but Hairy subverts this expectation by clarifying that he saw it in 1995, nearly a decade after the disaster. He mentions that his teacher was fired soon after, presumably for deliberately exposing young students to a highly traumatic event for no reason.
White Hat says that his first news memory was about the 2016 election (presumably the 2016 US presidential election), which was only three years prior to the publication date of this comic. As he is in his 30's, the fact that he can't remember any earlier news events surprises his friends, as he apparently was entirely unaware of news events for most of his life.
The final memory comes from Black Hat, who says he remembers "when we landed on the Moon". The implication is that he's talking about humanity's first Moon landing, which occurred on July 20, 1969, and that "we" refers to the United States (which launched the mission in question) or mankind in general. For people who where children in the 1960's, having the first Moon landing as a memory is quite common.
Black Hat subverts this interpretation by saying 'my second memory is my mom telling us we were moving to Earth instead, to blend in with the humans.' This completely re-interprets his first sentence, as it suggests that the "we" refers to himself and his family actually landing on the Moon. It also implies that he's an alien who landed on the Moon as a stopping point before relocating to Earth. Hairbun remarks that this revelation "explains a lot", implying that Black Hat's fundamental disregard for normal standards of human behavior make more sense if he is, in fact, not human. Of course, it's equally valid to conclude that Black Hat is lying simply to mess with the people around him, which would be fully in-character for him. This could also mean that Black Hat and White Hat are brothers, and thus, since it is unclear when they landed on Earth, it's possible the election was the first news episode White Hat ever watched.
Title Text
The title text gives the claim that flashbulb memories of big events can be unreliable. Randall (or another character in the comic, possibly Hairbun or Black Hat, who would want to spread misinformation) denies this claim, claiming to remember watching on CNN as the Challenger spacecraft crashed into the Berlin Wall. This is an inaccurate memory of these two events, as the Challenger explosion occurred in 1986 over the Atlantic Ocean, just east of Cape Canaveral, Florida, and did not occur near the Berlin Wall (in Berlin, Germany). Also, the Berlin Wall was intentionally demolished starting in 1989; it was not damaged by a space shuttle.[citation needed] It's also possible that this memory conflates those events with those of the September 11 attacks, since the latter did involve three winged craft crashing into and destroying landmark structures.