It happens when I’m driving. Or when I’m taking a break from work. Or in the split second when I’m waking up.

It happens a dozen times a day. Maybe more.

It’s a sudden realization that something is wrong — but I can’t remember what it is. That jolt makes me feel panic, as though there’s some terrible unspoken thing that threatens me — something I just can’t put my finger on. Something I can’t quite pull from my foggy memory.

The panic is physical. It does something in the center of my chest.

My heart starts to pound. In a brief instant, I become something like a caged animal ready to strike out at danger. But what is the danger? What is the threat? Why can’t I see it? What can’t I remember?

It’s an emptiness. It’s a hunger.

It’s an aching sense of longing for contentment. It’s a dull pain that I’ve become so accustomed to living with that I almost don’t notice — and then the panic returns and I’m painfully aware of the sudden rush of adrenaline and the awful feeling that I have no idea what’s wrong or what to do.

It feels like someone has died and I’m mourning the loss of a loved one. But no one has died. It feels as if someone has ripped some part of me out and left a gaping hole. But there’s no visible wound.

I keep coming back to the emptiness.

And every time it happens, the sense of panic — the sense of being a predator who’s about to become prey — goes away quickly. But the emptiness remains. The hole doesn’t go away.

My first instinct is to eat. It’s a visceral feeling. The emptiness has to be hunger. Food would soothe me. It would fill the emptiness. My rational brain knows better, but some deeper part — some child-like part that lives beneath the level of my rational self — screams in pain.

Something inside bargains with me. It begs. It pleads.

Just give me something — maybe ice cream — and the emptiness will go away.

The different parts inside me battle one another. The rational brain tries to be the reasonable executive function that explains to the child-like hurt that ice cream wouldn’t help. But the hurt — the hole, the emptiness, the panic — is so insistent that a part of the rational brain feels like saying, “Well, maybe one more time….”

The writer Edna St. Vincent Millay knew what this felt like. In a private letter, she wrote, “Where you used to be, there is a hole in the world, which I find myself constantly walking around in the daytime, and falling in at night. I miss you like hell.”

In the play, “No Exit,” Jean-Paul Sartre famously wrote, “Hell is other people.” But emotional hell can be the absence of someone, too. It can be the absence of love, of understanding — the absence of all those things that humans most desperately need once their basic physical needs are met.

Food won’t fill that hole. Sex won’t fill it. Recreational drugs such as alcohol won’t fill it.

Only genuine love and understanding will fill it, but that’s hard to find in emotionally healthy ways. At least for some of us.

If you’re around me when this panic strikes — and I feel a momentary existential terror and I briefly scream in pain inside without quite knowing why — you won’t know there’s anything wrong. You won’t know anything’s going on. My mask is tightly in place.

But inside, I’m fighting an exhausting battle. And, lately, it feels as though the emptiness is winning.