Celebrity culture be damned – stars were a lot more precious when we didn’t know every blasted thing about ’em. Proof lies in a creaky, 50-year-old “reality” series whose episodes today look primitive, naive and so powerfully heart-tugging that you can’t watch just one.

“This Is Your Life” had star bios pretty much to itself at its NBC TV debut in 1952, after sliding over from radio with host Ralph Edwards. He’d surprise celebs in a live broadcast by luring them to a studio under false pretenses, then presenting a parade of their families, friends, long-lost loved ones and other lives touched, in the most sentimental fashion imaginable.

A new DVD set from R2 Entertainment (clips at www.thisisyourlife.com) collects 18 half hours, each overflowing with more genuine shock, warmth and weepiness than a whole season of any slick show today. This is event TV. Look at these shy, excited, glowing faces in the thrall of honest astonishment, then compare it to our “reality” TV – no contest.

People weren’t so camera-trained then, so they’re awkwardly sincere and generally nonplussed. Roy Rogers can barely speak in his 1953 instant bio. Laurel and Hardy are stunned silent (again) a year later. Even Milton Berle is speechless in 1956: “Imagine Berle without an answer,” he babbles. And their stories were fresh. The public hadn’t been inundated with “news” of comic Lou Costello’s brush with death, drowned child and charitable works, or Olympic great Jesse Owens’ tough track to fame.

Even the 1970s color revival of “This Is Your Life” (taped in syndication) offered a fresh look at Johnny Cash’s battle with drugs, replete with arresting sheriff, grade-school teacher and Korean War buddies he hadn’t seen for years. Everyone’s googly like a baby. You will be, too.

But one thing is so old it’s new again. Eye that 1950s product placement – sponsor names plastered on the set, gifts presented with prominent brand mentions. In the midst of all this sentiment, it actually seems sweet rather than cynical. And there’s no going back there now.