“Did you hear about the Lindbergh baby?”

For decades, that mocking question has been asked of someone who has come late — very late — to some news discovery.

So it was today for me, and the NFL RedZone.

I asked, from the couch at the family home: “How long has this been going on?” Thinking it might be a recent development.

“For several years,” replied my nephew, who was too polite (or too young) to refer to the Lindbergh baby.

If any reader has not yet heard about NFL RedZone …

It is the simultaneous broadcast of every NFL game played on Sundays — a seven-hour block of time.

I was introduced to it today. I sat down, and there it was.

For those of us who have no warning, the concept is wrenching. You see the Saints and the Steelers playing, and think, “Oh, that’s the game we’re getting in the early slot.”

Then you look up a minute later and the Saints and Steelers are gone, replaced by the Chargers and Ravens. Soon followed by the Jaguars and Giants.

The NFL RedZone vow is to show every touchdown, preferably just before it happens. (Perhaps the inspiration for the name “RedZone”, the area referring to the 20 yards from the goal line.)

And if nobody appears on the verge of scoring, the director shows us a few minutes of whichever game is most interesting/important.

So, viewers careen from one side of the country to the other, chasing the most interesting game or moment. Blowouts get short shrift; aside from scoring plays, we saw basically nothing of the Rams and Raiders — which ended 52-0

And no fewer than nine games kicked off at 10 a.m. PST.

And the topper? No commercials.

That is huge.

Who would watch this?

Those of us interested in highlights — within seconds of them happening. Those of us with no specific rooting interest but like to see key plays. As well as NFL fantasy fanatics who want a 10-15 second head start on when their players have gotten into the end zone.

RedZone is a marvelous idea. A great leap forward in consuming NFL games. One of those things, though, that makes you wonder why it wasn’t done a decade ago.

It started five years ago, in 2009. (Which, yes, I missed; I also just found out about the O.J. trial.) I would guess the delay was about advertisers being worried that their pitches would go unseen.

The network is off the air, aside from that seven-hour span that covers all the Sunday day games. (Sunday night game not included.)

Generally, it means purchasing an additional sports package from your cable provider.

I resist most cable upgrades, but if I were living in the U.S., where games are happening in real time — during daylight hours — I might make a point of buying this.