For me, there are other factors:
Habit, maybe, for those few who actually do stay together. I don't know. I'm jaded on the subject. I believe that the aged couple exists only as the perception of a metaphor for that which simply isn't.
not necessarily but it helps
Experience new things together, share hobbies, and give each other space.
they must leave each
i think emotional a physical both a necessery bt i apreciate nore emotional
Not only that but honesty trust and faithfulness are key to a relationship