Love can mean various things to different people: sex, partnership, thoughtful gestures. But on all these fronts, it seems to me that love is declining in the United States, which is why I wrote a column for Valentine’s Day on the issue.Love can mean various things to different people: sex, partnership, thoughtful gestures. But on all these fronts, it seems to me that love is declining in the United States, which is why I wrote a column for Valentine’s Day on the issue.