Amnesia

loss of a large block of interrelated memories; complete or partial loss of memory caused by brain injury, shock, etc.
Contemporary Examples

On the negative side, the sheer tonnage of opinions can overwhelm and cause a degree of amnesia.
The Best Columns of the Year John Avlon December 30, 2013

The question of how to combat 9/11 amnesia while moving forward can feel like a Zen koan.
Bush Wrecked 9/11 John Avlon September 9, 2009

There is a heist motif running through the film and an amnesia motif and a noirish femme fatale motif too.
Danny Boyle, Director of ‘Trance,’ On His Favorite Psychological Thrillers Danny Boyle April 1, 2013

But how many sleep-deprived nights are you prepared to spend in nightspots like Les Caves du Roy, amnesia, or Billionaire?
Simon de Pury: Visiting 16 Studios of Los Angeles’s Top Artists Simon de Pury August 26, 2013

Forbes said she “imposed a form of amnesia” on herself after production on the first season of The Killing wrapped.
Michelle Forbes’ Good Grief Jace Lacob May 21, 2011

Historical Examples

Now if you let me out and I’m the first case that don’t get amnesia, I can tell the world about all this.
At the Post Horace Leonard Gold

In a lesser degree, amnesia only affects limited periods of life.
Metapsychical Phenomena J. Maxwell

For the name of the princess there is amnesia, as well as for the reason for his moon walking.
Sleep Walking and Moon Walking Isidor Isaak Sadger

What idiosyncracies of the narrator were concomitant products of amnesia?
Ulysses James Joyce

This is the breaking point, the moment when amnesia intervenes.
When Winter Comes to Main Street Grant Martin Overton

noun
a defect in memory, esp one resulting from pathological cause, such as brain damage or hysteria
n.

“loss of memory,” 1786 (as a Greek word in English from 1670s), Modern Latin, coined from Greek amnesia “forgetfulness,” from a-, privative prefix, “not” (see a- (3)) + mimneskesthai “to recall, cause to remember,” a reduplicated form related to Greek mnemnon “mindful,” mneme “memory,” mnasthai “to remember;” from PIE root *men- “to think, remember” (see mind (n.)).

amnesia am·ne·sia (ām-nē’zhə)
n.
The loss or impairment of memory.
amnesia
(ām-nē’zhə)
Partial or total loss of memory, usually caused by brain injury or shock.
amnesia [(am-nee-zhuh)]

A loss of memory, especially one brought on by some distressing or shocking experience.

Note: A common variant is selective amnesia; the term is applied to public officials who, when questioned about alleged wrongdoing, profess that they cannot remember.