A couple in an intimate pose10. Sexual intimacy is important.

A sexual relationship is what separates your relationships with friends, family and close colleagues, Blum said. Also, “put priority on being physical and physically affectionate beyond sexually,” Batshaw said.

11. There’s a difference between real intimacy and codependency.

One of the biggest misconceptions about relationships is the difference “between codependency and closeness or real intimacy,” Batshaw said. Codependency has this us-against-the-world connotation, where couples “do everything for each other,” he said. This creates the expectation that your partner will always attend to your needs.

But real intimacy or closeness involves attending to both needs. Say you come home after a rough day and all you want is for your partner to listen to what happened and cook dinner. But then you notice that they’re also a wreck. If you’re codependent, you recount your worst-day-ever experience and still expect the talk and meal.

If you’re intimate, however, you acknowledge that it’d be great if your partner could do these things, but it’s OK if they can’t, Batshaw said. You’re still honest about your awful day and explain what you need, asking something like, “Are you in a place where you can hear me now?’” If your partner is too stressed, cook together and talk afterwards. Most people, unfortunately, aren’t good at this, and it turns into a debate of whose needs are greatest, Batshaw said.

12. Making small changes may be harder than you think.

Does this example sound familiar? You ask your partner to call you when they’re going to be late because you get worried. But they don’t. Again. Inevitably, you’re left bewildered, wondering why they can’t do something so simple—especially when they know it upsets you and calling is as easy as “turn[ing] off the light switch when they leave the room,” Solley said.

Making small changes may be harder than you think.

But there are many reasons why they don’t call or make another small behavioral change. Solley believes that patterns from the person’s childhood are to blame. For instance, your partner’s mother might’ve nagged and smothered them, so they responded by “forgetting” to call as a way to create “a boundary against potential intrusion.” This “developmental change,” he said, “refers back to emotional patterns learned automatically and unconsciously during childhood development.”

And it goes back to attachment: If you developed an insecure attachment as a child, you might have more issues with developmental changes, he said. (“In insecurely attached relationships both partners tend to demand changes of each other, each thinking it should be easy for the other and feeling hurt—which often comes out as anger—when the other doesn’t follow suit.”)

What can you do? “Provide compassionate support and understanding of the old behavior.” It can take “weeks, months or longer” to make a change, “depending on the intensity and complexity of the underlying developmental emotional experience, and the abilities of both partners to understand and treat it with compassion.”

13. “The connection-protection balance” is a big obstacle in relationships.

People in relationships waver between wanting to connect with their partner and wanting to preserve their identity and protect themselves. As Solley said: “We want to merge together and feel the bliss of unbounded connection, warmth and security, but on the other hand we want to be independent, to make our own choices, have our own ideas, explore and avoid being hurt.”

Here’s a simple example: You say to your partner, “You’re driving too fast.” They respond with, “No I’m not.” Here, you’re being protective of your physical safety and they’re being protective of their skills and against your criticism. “Both are leaning on self-protection at the expense of connection.” The better alternative? Discuss your feelings (e.g., “I get scared when the car is moving this fast” and “I’m hurt that you don’t trust my driving.”); or empathize (e.g., “I know you’re confident in your driving but I need to feel safer,” and “Is my driving making you nervous?”).

14. “Your passion in your life should not be your relationship. [It should be] one of many different passions,” Batshaw said.

For instance, “very successful couples have high job satisfaction,” he said. “They get a lot of nutritive, sustaining and emotional self-esteem outside of their relationship from their work.” Partners also have their own hobbies and time to be with friends.

15. Relationships require “continuous work and maintenance,” Morrison said.

In our culture, couples aren’t taught how to maintain healthy relationships, Blum said. Instead, we think that love just fuels the relationship and it’ll somehow work out. Morrison agreed: There’s “this unrealistic view of relationships that once you say ‘I Do,’ you’re riding into the sunset.”

But relationships require “a lot of skill, attention and energy,” Blum said. Which is surprising to people, even though, for instance, everyone knows that continuous physical activity is key to good health. But we don’t “have the same mindset about a relationship.” In fact, you may need to work harder over time as your relationship experiences changes like kids, health problems and new careers, Morrison said.

Experts also underscored the importance of being compatible and participating in new experiences together.