This article by Mark Manson describes the very common marital experiences of 1,500 men and women who volunteered their thoughts on why many of their marriages work, and why many have failed.
The common themes are compelling, including having realistic expectations about relationships and romantic love, maintaining respect for one another through all of life’s unexpected changes, and supporting each other’s pursuit of independent interests.
It’s lengthy, but a worthwhile read.
What Makes for a Successful Marriage?