A theme developing in this blog recently has been the matter of learning lessons, particularly around the new edition of PRINCE2 project management and its principle of Learning from Experience.
A genre of reading that has been badly neglected by me has been history. Recently, in rapid succession I read two major histories: The Great Game
by Peter Hopkirk, and D-Day by Antony Beevor (the latter a father's day gift from my older son). Both of these gripped me, although in quite different ways.

In The Great Game Hopkirk unfolds the epic 19th century struggle between the two super powers of the day, Russia and Great Britain, for control of High Asia, a geographically romantic but inhospitable region. There was the drama of human folly and great heroism on both sides. But also as I read this in the early 21st century, there dawms upon me the appalling reality that imperialists have learned very little from this, particularly in executing a military campaign in Afghanistan; or, for example, from the fickleness of the British politics over this era, depending on whether the Tories or the Liberals were in power at the time.
Then I picked up Antony Beevor's Book. As a teenager I had read Cornelius Ryan's account of the D-Day landings, The Longest Day ,and more recently, like many people, had seen the movie Saving Private Ryan, so I was aware of the near disaster on Omaha Beach. Oh, but the shambles of the Normandy campaign in the following three months was a revelation.
For example, I'm no military historian, but I do know that nearly a hundred years before in the American Civil War the Confederates at Gettysburg were better integrated into units of calvary, infantry and artillery, and so had the edge in the early part of the battle, but that they failed to press home their early advantage. Amazingly, this lesson appears to been learned again the hard way in Normandy in the summer of 1944. It took some while for the Americans to 'get it' that they would be more effective if they coordinated armour, infantry units, artillery and air strikes closely. The British never did seem to learn this, despite taking on the lion's share of the panzer divisions during the campaign.
So what are the lessons here for project managers?
I believe we humans are less likely to learn and adapt from the experiences of others than we like to think. We are apt to dismiss the experiences of our predecessors as irrelevant and so we learn the expensive way. We really do need to take this into account in valuing and living the PRINCE2 principle of Learning from experience.