This talk given at the Vatican in November by Mormon leader, Henry B. Eyring. He explains clearly how to have a happy marriage. He says:
"Where there is selfishness, natural differences of men and women often divide. Where there is unselfishness, differences become complementary and provide opportunities to help and build each other. Spouses and family members can lift each other and ascend together if they care more about the interests of the other than their own interests."
Here is the full transcript if you would like to read it. It really explains how to have a happy marriage.
I have seen in my own 42 year marriage how differences, with lots of love, can can bring us joy.