Do You Have Imposter Syndrome? No matter how successful you are, if you don't have a little self-doubt lurking in the back of your mind, you're simply not human.

I was just reading about imposter syndrome, a fear that you're not really as capable as you're supposed to be. It's apparently common in successful people, especially high-achieving women like Facebook COO Sheryl Sandberg and actress Jodie Foster, according to Quartz. Fascinating read.

You can actually take a test to see if you have this anxiety-inducing condition and, if you do, to what extent.

I gave it a shot and came up relatively clean, which isn't surprising. At this late stage in life, I have a pretty clear picture of my strengths and weaknesses. After a lifetime of public achievements and more than a few humiliating defeats, I guess my self-image is pretty consistent with reality. As Popeye says, "I am what I am." No more, no less.

Of course my wife, who's always saying I'm full of s--t and just incredibly lucky, would disagree, but I don't think she understands why that is. Turns out she's the only person on Earth whose opinion matters to me, so she's the only one I even care to impress. Funny how it always backfires, though. You'd think I'd learn by now, wouldn't you?

Truth is, the longer I'm alive and the wiser I become, the more I realize just how little I know. At this rate, by the time the lights go out I won't know a blessed thing. Which is fine, since I'll probably be totally wacko by then. Guess I'm destined to leave this world the same way I entered it … without an intelligible thought in my head.

Related: 10 Behaviors of Genuinely Successful People

Back to the syndrome, the article implied that it's common in successful people who inevitably set the bar impossibly high for themselves. And when they achieve something, they simply set the bar higher, which is why they're never satisfied with their own accomplishments.

You've got to laugh at the irony: Overachievers are probably the last people who need to worry about that sort of thing. The real frauds are those who think they know it all – the self-proclaimed experts and gurus. They're the ones who are usually clueless, or at least undeserving of their overinflated egos.

Which brings us to another factor in the imposter phenomenon: maturity. When we're young, we think the world revolves around us. We often think we're smarter and more capable than we really are. But time and experience have a way of teaching us humility and putting things in perspective. That's called growing up.

Sure enough, I was arrogant and full of myself when I was young. I thought I had all the answers and hated admitting I was wrong, which was probably most of the time. But deep inside, I knew better. I was about as insecure as you could be. That's not imposter syndrome, just defensive overcompensation as a result of being young and dumb.

A few of the questions on the test seem to indicate that those with imposter syndrome often worry that their achievements were just plain luck. Perhaps one of the reasons is that our culture often associates success with privilege or luck, as opposed to individual capability or performance.

Related: Want to Be Successful? Have Fun. Seriously.

For example, I received this tweet in response to a recent article pointing out that success is based on an individual's work, decisions, and actions:

@Hennesseyedit @Entrepreneur @SteveTobak And a nice shot of luck, let's admit it

— Rupert Scofield (@rupertscofield) February 1, 2016

You hear that sort of thing all the time but it's a myth, and a damaging one at that. In my experience, success and luck are independent phenomena that are entirely unrelated. Rather, successful people make their own luck by working hard, making good decisions, taking risks, and being doers. That's not the same thing. Not even close.

Look, if you really want to know what drives highly accomplished people, it's usually a passion for their work. They're always striving to achieve more. The bar is never high enough. And while they sometimes project confidence and strength to hide deep-seated insecurities and fears, that's sort of the nature of the beast – the human condition.

No matter how successful you are, if you don't have a little self-doubt lurking in the back of your mind, you're simply not human. I guess we all have a little imposter syndrome in us.

Related: What Makes a Successful Entrepreneur? Perseverance.