To Quote Orwell:
"He who controls the Past, controls the Future. He who controls the Present controls the Past."
Liberals understand history very well. They just have a different view as to how it is to be used. While Conservatives see history as something solid and immutable which is useful in teaching lessons, the Liberal sees history as a lump of clay which can be reshaped and remolded many times over, and always, for a political purpose.
The Liberal must ALWAYS seek to re-write history. As an example: Barack Obama said, thousands of documented times, that if you liked your health plan and doctor, you could keep them under Obamacare. It was necessary to tell this lie in order to assuage public fear of a government takeover of health care (a political motive).
Now, when we know the truth, revisionist history kicks in: What Obama REALLY said, say the Libs, is that you could keep your old plan and doctor unless they failed to adopt the public mandates of the ACA, which they knew all along were poison pills. Note the rewriting of history before your very eyes: there was a nuance added three years after the fact, and they insist that it was always there, in plain sight.
Now, the fact that a bald-faced lie was told and the liar was caught doesn't mean anything, in a historical sense, to your average Libtard. They have been trained (indoctrinated) in the public schools and universities, and conditioned by the mass media, to forget that which is inconvenient immediately and then to deny it ever existed (Orwell called this Doublethink), and so far as the true believers and idiots are concerned, the lie will pass into historical truth, if you repeat it enough to numb what's left of their tiny little minds.
History exists in only two places, Orwell said -- in written records and in human memories. Academics, who will one day write the history of this time, are predominantly leftard, and so they will most likely write the leftard (politically-acceptable) version of history that shows them to have been right and prescient. The modern media (which is unapologetically leftist) controls minds -- no one in this country is ever away from the reach of leftist propaganda for more than a few hours, at most, per day -- shapes opinion, memory, tastes, and thought patterns on a daily basis, and shares much the same view as the academics.
And the good little liberal wanders about in a stupor, as he has been failed by both academics and media who have neglected to do their primary job of giving him unbiased education and information to help him make his choices, has the short-term memory of a garden slug.
Now you know.