There’s only thing worse that being caught reading Donna Hanover’s book “My Boyfriend’s Back: True Stories of Rediscovering Love with a Long-Lost Sweetheart.” And that is being caught reading it by your high school boyfriend (and three of his friends). This happened to me last week – and I’m still mortified.

Was it just a coincidence? Perhaps if one carries around this book – which examines the unsung benefits of reuniting with someone from your past -that missing person will simply show up. Maybe the book is a magnet for exes.

It could be. But mostly it’s a quick read in giddy celebration of the lucky ones who most of us would very much like to throttle.

Ms. Hanover – the former Mrs. Rudy Giuliani and first lady of New York City – wrote the book after reuniting in 2002 with her high school sweetheart, Ed Oster. It had been more than 30 years since they last dated. He had married someone else and divorced. So had she. After he saw the news about her divorce, he picked up the phone. And now they’re married.

Ms. Hanover decided to research the phenomenon and found that there are oodles of examples of couples with similar stories. Ms. Hanover trots out experts and therapists who say how much more deep and abiding the bonds are between people who fall in love early, then reunite later in life. But mostly the book is full of individual stories – by my count, more than 40 of them.

The couples in this book range from young never-marrieds who lost touch for a little while and then found each other to couples like Carol Channing and Harry Kullijian, who met in 1933 and lost touch for 70 years. (She wrote an autobiography in which she wrote fondly about her boyfriend from her early teens; an old friend pointed that out to Mr. Kullijian and he called.)

These stories are amusing, but they’re like popcorn. You can go on and on – until at one point you’re sickeningly full. It’s just all too good to be true. How is it that in so many cases, the white knight comes charging over when the damsel least expected it?

Well, Ms. Hanover does deserve some credit here. She has observed a funny thing about the way we live now. In the majority of these stories, either one or both parties have already been married and divorced. Whereas a previous generation might have married their high-school sweetheart the first time around, the people in this book took the long way. They parted ways, thrashed about, and then came back to the source.

So it turns out that it’s not just 30-something girls who are single. The pool of single people is like one of those constantly refilling champagne punch fountains – and every so often, someone comes along to drink from it. Who knows: You could be next!

The truth is that this book is going to give urban singletons a bit of anxiety. I mean, where is he already? Well, part of Ms. Hanover’s prescription is to start looking people up.

In Chapter 12 (“How to Reunite”), she suggests reconnecting at school reunions. The Internet is a good strategy, too. Basically, let old friends know that you’re looking for someone, anyone. You just never know who has been asking about you whilst you’ve been out there breaking hearts and having your own stomped upon.

I was glad to see that Ms. Hanover also includes a chapter on the pitfalls. “Not every reunion story is a fairy tale and not every beau is Prince Charming just because he comes from the old neighborhood,” she writes. There are creeps and junkies out there, don’t forget. There is the problem of relocating or commuting once you’ve found the old flame. And then there’s that unpleasant reality of marriages that are broken so that long-lost sweethearts can be reunited – which is just plain ugly.

These may be wonderful relationships, and if you’re lucky enough to have found one, it would appear that you’re in for a blissful ride. If not, you might find this book very useful as tinder.