Staying Connected
Remember that your relationship is not just a mental experience, but it is also both of your nervous systems communicating security to each other. There is a great difference between "I know she cares about me" and being cared for. We need, in our long-term relationships, experiences of being cared for and prioritized in order to maintain the cognitive belief that we are cared for and prioritized. Maintaining contact is an important way to do this.
There is a stage in development called object permanence and it occurs in the first 6-8 months of a baby's life. Before this stage, if an object is out of an infant's sight, they by and large forget that it exists. As they develop object permanence, they start to grieve the loss of the object, wanting it when it is not there. Around the same time they start to feel separation anxiety from caregivers. Part of working with separation anxiety in a child is comforting the child's feelings and having predictable returns to secure contact. Securely attached children learn to manage these small losses of contact with caregivers through keeping the caregiver in mind even when they are apart. But regular and predictable contact is important to keep this cycle fresh and alive, so it does not just become a mental game to override insecurity.
The same is true of our primary attachments in adulthood. We do not want to put our partners in a position of overriding insecurity with false narratives of "I know he loves me" when, in fact, they are not feeling loved. Instead, maintaining contact in a way that makes each of you feel secure is vital.
Everyone has different needs in this department. Understanding the kinds of connections that make you feel secure and the kinds of connections that make your partner feel secure is very important. Knowing each other in this way prevents expending tons of energy unsuccessfully relieving your partner's nervous system. Instead, you are spending a small amount of energy and your relationship is more calm and secure. For example - if your partner loves physical contact and yet you stay seated on the couch when they come home and just give them eye contact and a quick "hi", you are wasting energy and creating more insecurity. Spending a small amount of energy getting up and giving them a hug and kiss will, ultimately pay off in the long run as you will have a relaxed and confident partner.
Reminding each other that you are the most important people to each other is not difficult, but we do have to override the tendency to take each other for granted. At a party or large gathering, for example, we want to enjoy the company of others and connect with people we have not seen lately or have just met. Separation from our partner is natural and healthy. But at the same time, we want to keep each other in mind and give each other signals that we are still connected as the most important people to each other in the room. That might mean making eye contact and smiling at each other across the room, or finding the other person when we realize we haven't seen them for a while.
There are many other easy ways of staying connected. Sending sweet or funny emojis to each other in the middle of a long workday is one way. If you work from home, making sure that when you pass each other in the hallway or kitchen that you connect with a light touch or a quick kiss is another. When we are in a primary attachment relationship, being ignored or dismissed is deeply painful, it goes against the nervous system's wiring for security ("I am special to this person and I am always in their care"). Small gestures, even if you are doing something else (in the middle of a work call, thinking about a report you are writing as you make yourself lunch, walking out to the garage to get some tools) will keep each other feeling calm and secure.