I feel loved, cherished, and fulfilled in my relationship.

Loved and cherished come from another person. Fulfilment mostly doesn't. That one comes from work, from friendships, from something you make, from how you spend a Thursday.

Couples get into difficulty when the third gets outsourced to the first two. No single human being can be a career, a community and a purpose at once, and asking them to be is a heavy thing to hand somebody you like.

The good news is that it takes pressure off. A relationship does not have to carry your entire life in order to be excellent.

Where does the third one come from for you? It is worth being able to answer.