You have been with your partner for years. The two of you are starting to think about a wedding, or your families are, or you are wondering whether you need one at all. The pressure of the day already feels out of proportion to anything else in your life together. A hundred thousand dollars, a guest list, a venue, a date. Before you decide whether marriage is worth it, you should know that almost everyone considering it is confusing two completely different things. Until you see the difference, the question of whether to marry will keep feeling impossible. Once you do see it, the pressure of that day dissipates, and the answer becomes clear.

Most successful people in midlife look at marriage as a financial risk, and they are half right. The wrong spouse can cost you decades of your peace and half of what you built. The mistake is to blame marriage. The Harvard Study of Adult Development, the longest study of adult life ever conducted, found that married men lived seven to seventeen years longer than unmarried ones. But the same research shows that men in unhappy marriages carry a twenty-one percent higher risk of dying from any cause than men in happy ones. A good marriage adds years. A bad one takes them. The question is not whether to marry. It is whether you have found the partner whose partnership in your life over the next decades would give you back at least double what you brought to them.