If, like me, you grew up in the America of the 1970s, you knew it was a lot of things all at once. Practically every song on the Top 40 station I listened to had the word “love” in it somewhere, and in each song it was described in a slightly different way.

For Diana Ross, love was like an itching in her heart that she couldn’t scratch. According to a group called the Ohio Players, love was a roller coaster. “Love hurts,” one song lamented, while another went a step further by announcing: “Love stinks.”

For John Lennon (who both in and out of the Beatles used the word “love” even more often than the average pop songwriter), love was “all you need” and also “the answer.”

Not that love, and discussions of what it was, were confined to my radio. TV shows talked about it almost as much. “Love is all around,” sang the guy on the opening credits to “The Mary Tyler Moore Show” each week. Both “The Dating Game” and “The Newlywed Game” turned around the topic, while “Love American Style” reminded me that, whatever else love was, it was also thoroughly American.

The stars-and-stripes heart that introduced that show each week always made me think of a slightly updated version of the most beloved TV heart of all: the puffy black-and-white one that introduced the reruns of “I Love Lucy” I watched each day after school.

Speaking of school, reminders of love’s all-importance were present everywhere there as well. Each year, my home classroom seemed to feature one of those posters (inescapable in elementary and high schools all across America in the seventies) with the letters L O V E stacked two above and two below, with the O just slightly off-kilter like a book that had tipped over on a shelf.

In fourth and fifth grade, when the more accomplished readers in class started investigating genuine grown-up novels, girls could now and then be seen carrying around a copy of Erich Segal’s “Love Story,” the basis for the movie that taught the world the important—if to me puzzling—news that “love means never having to say you’re sorry.”

Last but not least, there were the bumper stickers. I grew up in Virginia, and somewhere in the mid-seventies every other car bumper started carrying a sticker announcing that “Virginia is for lovers.” Not only did I live in a world where love was clearly the most important thing going—I lived in a state where that was apparently even more the case than elsewhere.

These details all come from a very specific time and place, but a kid growing up today in New York City—or central Iowa—could provide his or her own equally long list of love-related images and slogans.

Why are we so obsessed with love? Why is so much of what we read, watch and listen to so crowded with the word and the idea—not to mention the heart that is its most popular visual symbol?

Part of the answer to that question is obvious. We are obsessed with love because we understand on an intuitive level what the Gospels tell us straight out: Love is all-important.

But there’s another reason why we humans are so love-obsessed, and it’s not so obvious. I have a suspicion we talk about love so much because we have forgotten an aspect of what it really is. It’s a way of thinking.

At first this might sound ridiculous. The last thing love would seem to have anything to do with is thinking. People who are in love do stupid, crazy things precisely because when you’re in love, you don’t think, right?

Yes—but that’s only one side of the story: the side in which love is seen as a kind of momentary madness that comes over us. But there’s another side of love: one that isn’t crazy and impetuous but profoundly sane and sober. Far from making us act irresponsibly, this variety of love brings out our deepest capacities for commitment and sacrifice. In short, this kind of love is thoughtful.

Try this experiment. Imagine that no one has ever told you anything about the way your insides work. You don’t know about your lungs or your kidneys, your stomach or your liver or any of the other internal organs that keep your body alive and functioning. For evidence of what’s going on inside you, you only have what you feel. Now, concentrate and see if you can tell where your thoughts are coming from.

If you’re like most people, it will be very hard, at least at first, to get away from the feeling that all your thoughts are coming from your head. We are so used to thinking of our brains as thought-making machines that we connect our thoughts to our brains without a moment’s hesitation.

But if you stay with this experiment a little longer, you might find that certain kinds of thoughts actually feel like they’re coming from parts of your body other than your brain. A mother worrying about her children might feel these heavy thoughts coming from her stomach. And when she stops worrying about those children and concentrates on her feelings of love for them, that same mother might experience those thoughts as coming from her heart.

The heart is the true human center, and in times past it was taken for granted that the deepest, most serious and most essential thoughts came from it.