Have you ever noticed how the same historic event is often presented entirely differently in two neighbouring countries?
For example in Britain, Nelson is seen as a war hero, while in Denmark he is remembered as a war criminal.
The stories a nation tells about itself isn't so much self-delusion, as a willful projection of values upon the tapestry of history, accentuating what the writers want to be seen as important about their nation.
Do they see it as honest? Picked upon? A survivor? A conqueror? Inventive?
British writers, for example, often highlight events to reinforce the claim that the British as cynical, beset by bureaucracy and put too much importance upon orderly queueing. Even when there is a Russian in the room. :-)
Sometimes they do this out of pride, to distinguish themselves from a particular group, sometimes to promote hope when things are bad, sometimes to re-interpret past events they are ashamed of, or justify things they want to do.
How has the story your nation tells about its national character changed over the past 200 years? What changing circumstances do you think lead to the altered importance placed upon particular characteristics?