It happened again this morning. I went to Wal-Mart to pick up a prescription refill and to buy a few other items. In the store, I felt nervous, as if something were about to go wrong. My chest felt tight, right across the diaphragm, and my arms and knees trembled. If I were doing something wrong, the feeling would have made sense. If I was entering a dangerous place, the feeling would have made sense. But I was shopping in Wal-Mart, so there was no reason for me to feel that way.

Have you ever been driving down the street, noticed a police car off to the side, glanced at your speedometer, and realized you were going five miles over the limit? Do you know those seconds of worry, wondering if the police officer was tracking your speed with radar, wondering if the officer is going to pull you over or let you go? That’s the feeling I’m describing.

They call it anxiety. When it happens suddenly and strongly, the condition is called anxiety attacks or panic attacks. When it is more of a general, on-going feeling, it is called free-floating anxiety. By any name, it is not a good feeling. It’s like a constant caffeine high, or a constant adrenaline surge. It’s as if I’m always looking over my shoulder to see who’s about to attack.

Whenever I leave home, I feel as if I forgot to bring something important. I cannot drive to work without checking at least once to make sure my name badge and electric security key are in the car with me. I’m a cautious driver and an alert driver, always prepared for things to go wrong, always prepared for some other driver to make a stupid mistake. If I’m not worried about the other drivers, I worry about my own car. Is something about to break down? Will I have a flat tire today? Why do I smell gasoline? (Because I just drove past a gas station.) What was that noise, and what does it mean for the immediate future of the car?

Can you believe that people pay money to feel this way? Some people ride roller coasters. Some go to horror movies or watch them at home. Some visit haunted houses. I’d gladly trade them this thrill for a calm day, a confident day, a day when I don’t feel as if something is about to go wrong.

Am I getting help? You bet I am! The prescription I needed to refill at Wal-Mart is medicine that is supposed to help me overcome this anxiety. I think it might be doing me some good. How ironic, though, to wrestle with that feeling on the very trip that is supposed to be providing a solution to my anxiety.

My immediate family and my therapist know I feel this way. I keep it hidden from everyone else. I’m sure that no one shopping at Wal-Mart sensed my anxiety, although the cashier might have wondered why my hands were shaking when I took out my wallet and paid for my purchases. Most of the time I blend into the crowd, act just like everyone else, and keep control of myself. I do not let people know how I feel on the inside.

I could be someone you know. I could be your co-worker, your next-door neighbor, your bartender, or your barber. No, maybe not your barber—that’s not a good idea. The point is, you will never know how many people in your life are struggling in ways that you never imagined. It’s all around you, invisible, hidden right in front of your eyes.