Each generation has moments that are indelibly imprinted in its collective memory, moments that are recalled and retold time after time.

My generation knows precisely where we were when John F. Kennedy was assassinated. For our parents, the defining moment of their lives was Dec. 7, 1941 — 75 years ago today.

It was Sunday afternoon on the East Coast and families were finishing their traditional Sunday dinner. Many had turned on the family radio. Up and down the coast, they may have been listening to the live coverage of the Giant and Dodgers baseball game, the National Vespers program or a concert by the New York Philharmonic. In Virginia, many were listening to the Sammy Kaye musical program, Those were pretty much the choices available.

Then, at 2:22 p.m., the Associated Press issued the bulletin that would change the world — and, coincidentally, usher in a new era of nearly instant news. The AP bulletin was the first public report of the attack on Pearl Harbor, and it occurred while the attack was still underway.

Within minutes, news networks had confirmed the initial report to their satisfaction and were breaking into the Sunday afternoon programs to announce what was happening.

I recall my parents saying that they were visiting their neighbors, Grover and Jean Yeoman, and heard the announcement over the Yeoman’s radio.

(A story in today’s Times relates similar remembrances by local residents interviewed this week.)