i am just old enough to have experienced 9/11 when i was in elementary school. it was a similar change to society to how covid screwed everything
when i was a child, there was no security in airports. like literally NONE. you could walk in and buy a flight with physical cash. if you wanted an international flight, there was a metal detector like you might find in a night club
government ID and drivers licence did not have your photograph on it, and some state drivers licenses were printed on non-laminated card. there was also no functional internet surveillance (there were no good search algorithms or tools in the early internet, so the government couldnt search either).
but the real big change, which is kind of what everyone felt i think, is the whole world was celebrating the end of the cold war and so vehemently protested going into the middle east, and the government just did it anyway. the largest protests in the history of the west were against that war and it was all totally ignored https://en.wikipedia.org/wiki/Protests_against_the_Iraq_War
then we got the PATRIOT act, NSA/CIA spying on the population, heavily armed police. btw, in the 1990s you would NEVER see police with assault rifles and armoured trucks etc except for swat teams in major cities and the ATF. The idea of your local police department having a heap of military equipment was crazy. a great example of this is the LA riots in '92 - they had to call in the army and the national guard because the police simply werent equipped for it
and they would run these polls on tv, like gallup polls, falsely claiming that 20%+ of people publicly supported the war
even though it didnt affect anyone as much personally, it was the turning point where the gov just started brazenly ignoring people and introducing the heavy duty surveillance state, which was especially painfully felt in aus, canada, new zealand, the us, and the uk. and covid19 tyranny was only possible because of what bush did in response to 9/11 - it physically could not have happened in the 1990s as there were no government agencies that could have done it