Jeannie Assimos, director of content for eHarmony's blog, agrees about the importance of compatibility. "The most important thing is to know what you want and know what you can and can't deal with," Assimos says, recommending that singles aim for a list of 10 qualities they'd like in a partner in terms of beliefs and values. "The more similar you are, it's just easier – you get each other more." But that's not say you should sacrifice chemistry, she says. "You have to have that."
But what exactly even is chemistry? Physical attraction plus a certain connection, explains sex and relationship therapist Laura Berman, author of "Loving Sex: The Book of Joy and Passion." "It's a mysterious and beautiful formula that you can't necessarily force or create," and one that's critical for a lasting union, she says. Still, "I think the most important quality that you need in a mate who's going to go for the long haul with you is someone who is open to learning about themselves and willing to change and be flexible and who is resilient – because you're going to have crises, you're going to have conflicts, you're going to look at things differently, you're going to go through hard times in life and you have to be able to communicate."
[Read: How to Be a Good Listener.]
And as the years go on, and the feelings of lust are likely to fall into jeopardy, it's important to remember to seek the qualities that caused you to fall in love in the first place and express appreciation for them, she says. That creates a positive cycle that pays off with encouraging more of those qualities and more appreciation for both people involved.
Perhaps, that way, whether it's three traits or 10 that you found in your partner, you can consider yourself lucky.