Video highlights

Finkel opens with a scene from the movie Ghost, in which Patrick Swayze tries to prove his identity to Demi Moore through a psychic, with Whoopi Goldberg as the only person able to hear him. His first message, 'Tell her I love her,' is too generic, so he sends 'Ditto' instead, the couple's secret code for 'I love you.'

Finkel borrows the term leitmotif from music and defines a lovemotif as a recurring set of shared experiences and meanings that uniquely define a relationship. It includes words that pass the 'ditto test,' private in-jokes and a distinctive moral code.

He says he only recently realized how important lovemotifs are, and that they matter more today than ever before.

Finkel says people in much of the world now feel increasingly obligated to be true to themselves. In a long-term relationship, that pursuit can seem at odds with commitment.

In the past, divorcing couples felt ashamed. Now, he says, people can feel shame for staying if it makes them feel inauthentic, based on the assumption that they must choose between themselves and the relationship.

Finkel uses La La Land to show the dilemma. Ryan Gosling and Emma Stone have a strong connection, yet the relationship fails, not for lack of love or support but because the relationship never gets a voice in their individual choices.

Finkel notes that most people feel lucky that the person they go home with is their own partner. The common explanation is that we have a set of attributes and must find a partner whose attributes fit, like a gear.

What matters is smaller and deeper: a phrase gets repeated, a joke sticks, a ritual forms, and a private world takes shape across countless tiny interactions.

Finkel defines compatibility as building something that never existed before. He gives an example from his own relationship: in their earliest months together, 'belly full of wine,' a line from a Beatles song, became the couple's private signal for 'I love you.'

As couples repeat and riff on tiny moments, those moments stop being random and become a lovemotif, part of who they are. Once the relationship becomes part of identity, being true to it stops feeling like self-denial and starts feeling like authenticity.

Returning to La La Land, he says Emma and Ryan realized too late that loyalty to their private world would have been an expression of authenticity, not a betrayal of it.

Finkel and Lydia Emery asked couples to describe their lovemotif. Examples include a October horror-movie calendar, a song sung to a baby daughter every Shabbat, and a joke about surfing on a shrimp sandwich.

Tracking couples daily for weeks, they found that those who leaned more strongly into their lovemotif on a given day were happier that day than on days they leaned less. Finkel says the article is still being finalized.

Finkel acknowledges the common story that relationships lose novelty, excitement and passion over time. He agrees some of that goes, but argues that something deeper grows: a shared history and private world that means nothing to anyone else and everything to the couple.

Finkel gives three steps for building a lovemotif. First, find it by noticing moments when something uniquely 'us' starts to emerge. Next, feed it by revisiting those moments and turning them into rituals and inside jokes.

Finally, fight for it against distraction, drift, and the belief that small things cannot really matter. Finkel closes by urging viewers to build their lovemotif while there is still time, so that when it matters most, one word will be enough.