I belong to a class of people who might charitably be called overthinkers — who, when confronted with (gasp) making a decision, will kill any semblance of clarity by bludgeoning it with what ifs.

In matters of the heart, and especially when (hyperventilate) talk turns to commitment, we overthinkers just about lose our minds. What if the love fades? What if there's someone else who's a better fit? What if his/her quirks become intolerable? What if I think this is the person I want, but I'm wrong?

At the core of those unanswerable questions lies the most impossible question of all:

How do I know that I have found The One?

Ideally, those of us paralyzed by romantic indecision would like the heavens to send an unmistakable sign, or for researchers to devise a mathematical formula predicting long-term bliss.

Instead, the popular response to such hand wringing is the infuriating: "When you know, you know."

Robert Rigsby, a judge on the District of Columbia Superior Court, recalls in detail the evening he stumbled into a party and met his future wife.

"I walk in the door and immediately see a woman in a black-and-white skirt and a black top, and she was eating a turkey sandwich," Rigsby, 48, recalls. "And she had mayonnaise on her face."

He offered her a napkin, asked her to dance, and for the next three hours they danced and talked as though they'd known each other all their lives. It was Sept. 21, 1991, and by 9 p.m., Rigsby said, "I knew beyond a doubt that this was the woman I would marry."

On Thanksgiving, their families met.

On Christmas Eve, Rigsby proposed.

"I feel like I loved him almost as soon as we met," recalls Anna Blackburne-Rigsby, 48, a judge on the District of Columbia Court of Appeals and Rigsby's wife of 18 years. "I liked his optimism, I liked his honesty, I liked his courage, his crazy, wild sense of humor, his sense that the glass is always half full."

In previous relationships, Rigsby said, "I could always find a reason why not. In Anna's case, it was easy. I could only think of why."

Being emotionally ready to commit is essential, they said. So is knowing what you want.

Blackburne-Rigsby said she vividly remembers feeling anxious that she would never find the right man, and her grandmother counseled: "When the student is ready, the teacher will appear."

Blackburne-Rigsby, about 30 at the time, then wrote in her journal what was important to her in a husband: honesty, optimism, family, grounded faith, joy for life.

"I never would have thought in a million years the sort of package my dream would come in," she said. "Had it been another time in my life, I might have missed it."

Not all great couples fall head over heels immediately.

Xochitl Pena was not immediately attracted to Shad Powers, her co-worker at a Michigan newspaper, in part because of their freakish height difference: She's 5 feet 1 inch; he's 6 feet 7. They were friends for two years before Pena, with the help of a bit of alcohol, allowed things to get romantic and started seeing him in a new light. (Powers always was smitten.)