Imagine this.

You are a boy, living in a child’s blissful unaware. You are not terribly different from other kids. Maybe you play stickball in the street and pretend to be Joe DiMaggio. Maybe you listen to “The Lone Ranger” on the Philco. Maybe you’re crazy for Superman.

Maybe it’s a good life.

Then comes that sudden Sunday in December. All at once, everyone is angry about something bad that happened at a place called Pearl Harbor, and people you know — people who know you — are staring at you as if you are no longer who you always were.

Two months later — 75 years ago this week — there is news about a new executive order signed by President Roosevelt. Soon, the poster starts appearing on lamp posts. The headline reads: “Instructions to All Persons of Japanese Ancestry.” It is an evacuation order.

As a child, you know nothing about the column in the San Francisco Examiner where Henry McLemore wrote: “Let ’em be pinched, hurt, hungry and dead up against it … Personally, I hate the Japanese. And that goes for all of them.”

And you didn’t hear how Assistant War Secretary John McCloy said, “If it is a question of the safety of the country [and] the Constitution … why, the Constitution is just a scrap of paper to me.”

All you know is that suddenly, with maybe a week’s notice, you are on a train, being taken away from your Philco and from stickball games, from Superman comic books, from, well … everything.

Maybe your name is Noriyuki “Pat” Morita, and you will someday be Mr. Miyagi in “The Karate Kid” movies. Maybe your name is Hosato Takei, and as George Takei, you will become the original Mr. Sulu on “Star Trek.” Maybe your name is Norman Mineta and you will be a congressman.

But in the desolate camps to which you are exiled, it doesn’t matter who you are or what you might someday be. In the camps, as they say, “A Jap is a Jap.”

So in the camps, you live behind barbed wire, under armed guard in tar paper barracks with toilets where you must do your business in public view.

You live with inferno heat, aching cold, and gritty dust. Yet, you struggle to hold on to who you used to be.

You play baseball. You draw and sing. And you go to school, where every morning you stand, hand over your heart, and recite, “I pledge allegiance to the flag of the United States of America …”

Seventy-five years later, communal memory recoils from what the United States of America did to you. And as we tend do when memory indicts conscience, we choose to forget.

So many of us no longer know what happened, how you lost your businesses, your homes, how your lives were never again the same.

As many of us forget the story, we also forget its moral: how fear can interdict reason, make you lash out with hatred at harmless people.

Thus, some of us cheered recently when a new executive order was signed and our airports turned to chaos. Some of us echoed McCloy: “The Constitution is just a scrap of paper to me.”

But the rest of us were saddened by what America has done to itself — and to countless innocents — in the spasms of its fear.

The rest of us were stunned by what Winston Churchill called “the confirmed unteachability” of humankind.

We never learn, do we?

Imagine you are a boy, living in a child’s blissful unaware, not terribly different from other kids. Maybe you play hoops at the park and pretend to be Michael Jordan. Maybe you watch Power Rangers. Maybe you’re crazy for Spider-Man.

Maybe it’s a good life.

But then comes a sudden Tuesday in September.

IMAGE: War Relocation Authority – 210-G-2A-572, Records of War Relocation Authority, Record Group 210; National Archives at College Park, College Park, MD. Wikicommons / United States Department of Interior.