Consider the big news stories - the death of Diana, Princess of Wales; the World Trade Center being destroyed; the London Tube bombings etc. - and you'll notice a common thread. Namely that they happen out the blue. We all went to bed on 30 August 1997, 10 September 2001 and 6 July 2005 not expecting that the following day was going to be anything out of the ordinary. Some events we know in advance - we know when the Scottish independence referendum, the general election, the American Presidential election are going to be.
But the big events that dominate the years that follow them are a combination. On one hand we can have 20/20 hindsight and see a progression of events that led up to them. But on the other hand they are genuinely unexpected.
Today sees the centenary of Franz Ferdinand being assassinated and this led to the First World War weeks later.
I remember one exercise we did in A-level History when we were examining the many causes for the War. And that was to split into 6 groups - I think we were the UK, Serbia, Germany, Russia, France and Austria-Hungary - and debate whose fault the war was, using our knowledge of history. One thing we were all agreed one was that poor Serbia was the innocent party.
A couple of years later I popped back and caught up with my former teachers. I asked my History teacher whether she still did that session. Yes, she did. And I wanted to know whether - given this was the midst of the Yugoslav Civil War and we saw reports of Serbian aggression - her students were as keen as we had been to see Serbia as the blameless country.
She replied that she found her students were more willing to put some of the blame for the War onto Serbia.
The facts of what happened in 1914 hadn't changed. Perception had changed as we view history through our own perspectives.
In sci-fi there is retconning - retrospective continuity. And we all do it.
Retconning isn't when a fresh understanding is put on events based on evidence that has come to light later. One year we think that a celebrity is doing a lot for charity as he's a genuinely charitable man. When we reinterpret that as him using charitable causes to get close to children to sexually abuse, we are not retconning.
Retconning is where we take what someone later did and reinterpret their past through that lens, without evidence. For example, anyone interested in political history will know that in August 1931, Labour Prime Minister Ramsay MacDonald ditched most of his Cabinet and formed a Government with the Conservatives and Liberals. For some on the left, MacDonald must have been planning that for a very long time.
MacDonald first became an MP by winning Leicester in the January/February 1906 general election. By "winning Leicester" I mean becoming one of its MPs (it was a 2-seater), unseating the Conservatives' John Rolleston - who had been elected at the Khaki election of October 1900, the final general election of the nineteenth century and the last held in the reign of Queen Victoria. Rolleston had ended the tradition of Leicester returning 2 Liberal MPs which dated back to the July 1865 general election. In 1900 MacDonald had stood, but come fourth.
In 1906, due to the Lib-Lab pact, Leicester's Liberals only put up one candidate. But just suppose MacDonald had been craving high office. Labour's position after 1906 was as the fourth largest party in the House of Commons. Sure, in the following elections (January/February 1910, December 1910, December 1918) they slowly increased in size, but a reasonable comparison is the slow growth of the Liberal Democrats from April 1992 onwards (May 1997, June 2001 and May 2005 all saw the Liberal Democrats increase in number of MPs).
But no-one could have expected that by 1924 there would be a Labour Government - with MacDonald leading it - and the Liberals would have collapsed. That is equivalent to the Liberal Democrats going from 20 MPs in 1992 to not just being junior coalition partners after the May 2010 general election, but forming a Government on their own with one of the 1992 intake as Prime Minister.
If MacDonald had craved office, surely the logical thing would have been to ask the Liberals to run 2 candidates in Leicester in 1906 - with him as the second one - so he could then develop a career beginning as a backbench Liberal MP. This was the Liberal party at its height, unaware of the collapse to come.
Whenever dealing with people, countries or organisations, always avoid retconning their past based on what they did later on.