Sometimes we don’t recognize the best moments in life. Next Sunday is Father’s Day. Go out and have a catch. You’ll be better for it and so will your kid.

Harold Theurer Jr. is author of (ITAL) Hey Dad! Let’s Have a Catch. (END ITAL) He didn’t plan any of this but he’s changing the world, one catch at a time. In many ways the rhythmic thwack of ball hitting glove is our national heartbeat.

Shortly after 9-11 Theurer was downsized from Wall Street after 18 years on the job, most of that time spent tutoring young brokers. At home in Brooklyn, with his wife Lynne’s blessing, he decided to write a children’s book to honor his father, who passed away 11 years earlier. The project took about three years to complete, but now Theurer is discovering his little book is connecting with generations of men and even has been turned into a one-act play.

On Father’s Day he will touch home plate when he offers a reading at the Baseball Hall of Fame in Cooperstown. Then he will play catch with his 12-year-old son Harold.

“For me it’s a Field of Dreams moment,’’ Theurer says, noting the famous line spoken by Ray Kinsella: “Hey … Dad? You wanna have a catch?’’

Answers John Kinsella: “I’d like that.’’

Harold Theurer Sr. worked two jobs. His favorite Yankee was Lou Gehrig, another Iron Horse. In between jobs, he found time to play catch with his son nearly every day. It wasn’t just the catch; it was the precious time spent together as father and son communicated in a unique way.

“You’re face to face, encouraging your kid saying, ‘Nice throw, good catch, get under it,’ all the things my father used to say to me,’’ Theurer says. “I call all of it the Zen of the Catch. You just don’t see as much of that anymore. Someone else coaches our kids. We’re all on our treadmills running, sometimes you’ve just got to step back and start throwing.’’

When he first tried to get literary agents interested in his book, Theurer, 51, heard comments like, “It’s not edgy enough.’’

“I guess every father son relationship has to be like Bart and Homer Simpson,’’ he says. When Theurer’s former high school English teacher Larry Hayden liked the book that proved to be enough for Theurer.

He found his own illustrator, William Baxter Bledsoe, out of Jonesborough, Tennessee and his own publisher, RJ Communications in Manhattan.

Former major league pitchers Jim Kaat and Al Leiter wrote to Theurer, telling him how much they enjoyed the book and what it was like to play catch with their dads. Nearly every major leaguer can relate to Theurer’s words and this is a message for anyone who has played catch with a parent.

It could be a mother playing catch with a son or daughter. It could be a three-generational catch, grandfather, father and grandchild. It’s about taking time to relate. And it can continue well into adulthood. There should be a national “Have a Catch’’ day. A number of ballparks are beginning to offer “Have a Catch’’ promotions.

Theurer tells me about the last catch he had with his dad.

“It was July 9, 1990, it was my father’s 72nd birthday, we had a barbecue at his house, sang Happy Birthday, cut the cake and my wife and my mother went inside,’’ he begins. “I just happened to pick up a tennis ball that was laying in the yard. We started playing catch. No words were spoken, just the rhythm of the catch. We had our last catch. It was something I will never forget.’’

Six weeks later his father passed away.

“Five years later my son was born,’’ Theurer says, “and I couldn’t wait for him to start walking and talking and we started playing catch.’’

The rhythm of the catch was reborn.