The problem is that people's short memories of bad events aren't necessarily a good thing. Insofar as an individual is concerned, not suffering for an extended period after the distressing circumstances are over is a good thing, showing a healthy coping strategy that preserves said individual's mental health long-term. But, on a larger scale, forgetfulness of past hiccups often costs a lot. Back in the days of SARS, there was a lot of research into prevention of infectious disease spread by air transport. There were many industry-leading scientists coming up with all sorts of smart and totally realistic ideas of how to make aviation safe from a contagious disease perspective. Self-disinfecting materials for aircraft interiors, HEPA filters, remote thermometer control in airport terminals, ozone or UV disinfection of suitcases - you name it, it was on the table. But guess what - as soon as SARS went away, funding for all those programmes was axed and lots of the brilliant concepts were shelved in favour of "why invest into improving something which works just fine the way it is". There was a short resurgence in interest towards some of those projects during the Ebola outbreaks of 2014-2016 - but again, more was said than done. Until the chickens came home to roost in 2020.