A rant regarding the millenium bug "scaremongering" - My DH spent eighteen months working for a big company just before 2000. They used software to monitor and control the delivery of a utility to customers nationwide, and to measure their usage and bill them.
That software had been written for computers with far smaller memory and operational space than those in use now. To refer to the dates as 1975, 1989, 1994, would have needed a hundred times as much space as referring to them as 75, 89, 94, and so on, and that space just wasn't available. So to save valuable space the dates kept in the database were referred to by the shorter.
This was not just in one part of the software - it was all through it. As the software operated, it used the shorter dates in doing all the calculations needed to keep the whole country supplied and the correct amount billed. Every part of the software had to be at least one hundred times as big. If one date failed, the whole thing could have come to a halt. The same was true of software for home computers which had been written earlier for less powerful machines.
At intervals the software had been altered here and there, and it was hoped that all the references to the shortened dates had been removed, but until midnight on 12/12/1999 it was impossible to be absolutely sure without manually checking every line of code That is what took DH and several others eighteen months to make safe. Replacing the complete software package would have caused even more upheaval and expense.
Every utility had to do the same thing, to make sure that they would not fail. So they did - they spent time and money getting it right so that there were no problems They had no alternative, and it worked.
The result - a lot of people saying "What was all the fuss about - nothing went wrong!" Like saying "Why do we bother using safety devices on machinery - fatal accidents are just about non-existent"