"I want to grow old with you," people will say to a beloved life partner. At the beginning, maybe.
A lot of other things get said over the years, some of them downright hurtful. People and relationships evolve, and it takes some work to keep a couple together.
Daphne de Marneffe, a Bay Area psychologist, guides couples through the bad parts in a book called The Rough Patch: Marriage and the Art of Living Together. She offers a framework in our interview from 2018.