By SEAN DIETRICH

Let’s talk about confidence. Self-confidence. Not the corny brand of confidence found in many self-help books where you repeat a motivational key phrase before the mirror for guaranteed success — or your money back!

No, I’m talking about the kind of unwavering confidence found within exceptional people who routinely sing karaoke or pass highway patrol vehicles on the interstate. Confidence.

I bring up this subject because today I was standing in line at the supermarket when I met a retired psychologist. She was mid-eighties, with white hair and Coke-bottle glasses. Her name was Doctor Don’t-You-Dare-Use-My-Real-Name.

We got to talking and I casually asked the old physician which mental health problems she encountered most during her career.

Her answer came quickly. “Lack of confidence.”

“Really?” I said.

“Definitely,” she said as our cashier was ringing up the old woman’s — I swear — box of prunes. 

I was surprised by her answer. I was expecting her to say the most frequent disorders were anxiety, depression or as in my case, clinically obsessive avoidance of mowing my lawn.

“Well,” answered the shrink. “Lack of confidence is a problem that helps fuels those other problems. People who quit believing in themselves fall apart or they overcompensate. Both are dangerous.”  

Statistically, two-thirds of Americans suffer from a lack of self-confidence. In one study, researchers found that a quarter of people under age 35 admitted to disliking themselves. And in a recent survey, eight out of ten teenage girls admitted to practically hating themselves.

“Lack of confidence isn’t just a little problem,” said the clinician. “It’s the iceberg that sank the Titanic.”

By now, the cashier and everyone else in line was listening to our conversation as the doc went on to explain that most people without confidence have lost the ability to think positively. Which is a fatal problem.

“Unconfident people don’t believe anything good can happen to them personally. They don’t feel they deserve good things. They don’t believe they will heal. So they expect the worst, and you know what? They get what they expect.” 

The doctor must be right because I receive a lot of letters from people who don’t have much confidence. Most of these letters are from people going through difficult periods. People who hail from all walks of life. Young people, older people, college students, sick people, grieving people, single parents, people starting new jobs and first-time bungee jumpers.

Yes, bungee jumpers. Last night my phone vibrated informing me that I had an email from a guy named Lane who was about to bungee jump. The decision came after Lane lost his father this year.

Lane explained that his jump-site is located on an obscenely tall bridge spanning over a steep river gorge in northern California. He sent a picture that made my cheeks tighten; and I don’t mean the ones on my face.  

Lane wrote: “I’m scared to do this … Any advice on how to face my fears?”

If Lane is reading this right now, I’d like to offer a few helpful words: Are you out of your freaking mind?

No, wait. What I meant to say is, you’re going to be okay, Lane. Do you know how I know this? Because anybody who attaches a rubber band to their ankle and leaps off a bridge has a shipload of confidence. And according to the psychologist in the supermarket …

“Confidence is all it takes.” 

“All it takes?” I asked the doctor skeptically. “Isn’t that oversimplifying things?”

The doc shrugged. “Maybe, but I’ve seen too many miracles in my time to know that people who believe in miracles are the ones who get them.”

At first, I’ll be honest, all this self-confidence talk sounded vaguely like those motivational speakers from the 1980s with the giant hair and the plaid sport coats.

But then I got to thinking, there must be a reason why those motivational as-seen-on-TV gurus were able to make successful careers out of catchphrases like: “if you can believe it, you can achieve it,” or “find true joy with only five easy payments of $39.95.” Confidence.

Sadly, I have struggled with confidence my whole life. I was the chubby kid playing outfield who grew up in a broken home. Guys like me didn’t grow up believing in much.

And I’m not alone in the self-esteem department. I’m thinking of the guy who emailed me yesterday about how his spouse of thirty-odd years left him.

I’m also thinking about Brady, whose mother attempted suicide in his garage last week.

I’m thinking of Karen, and the serious illness she was diagnosed with last month.

I’m thinking about the man named Phillip, who grapples with clinical depression.

The doc is clear to point out that there is no one-size-fits-all solution for mental health issues. It’s not nearly that simple. She’s not saying that. But the good doctor does have a message for you just the same. And I received her message loud and clear as she was pushing her buggy through the supermarket exit.

I asked her, on the record, if she had any words of wisdom for those struggling with confidence. People like me.

“I sure do,” the old woman replied with a smile. “You got this. And God’s got you.”

Or your money back.