I’ve written a lot about inferences, assumptions, and illusions – and how they relate to one another. Sometimes the line between inference (the act of deriving a logical conclusion from a premise believed to be true) and assumption (accepting something as true without proof) becomes fuzzy. Recently, I’ve had some head-shaking experiences that got me thinking about this fascinating threesome yet again.

Let me start by pointing out that there are, in fact, many things that we know exist, through firsthand experience, even though we cannot see them. We know that wind exists, but we can’t see it. We know that sound waves exist, but we can’t see them. We know that air exists, but we can’t see it (though we can see foreign particles in the air, which is an entirely different matter).

Even more intriguing is that we often can’t see things that not only are visible but are right in front of our eyes.

The Light-Dimming Mystery

Last week, for example, the lights in my office ceiling got very dim – so dim that I could barely see the papers on my desk. I assumed (that ever-dangerous word) that something was wrong with the electrical wiring.

I repeatedly turned the lights off and on throughout the day, hoping they would regain their normal intensity. No luck. Finally, I called an electrician.

When the electrician showed up on my doorstep the next morning, I led him downstairs to my office while explaining the problem. As he reached the bottom of the stairs, he asked, “Have you tried the dimmer switch?”

I thought he was trying to be funny. I turn my office lights on and off every day, and I knew I had never seen a dimmer knob on any of the switches. The problem? I had made an assumption that all dimmer switches are knobs. Unwittingly, that became my premise for determining that there were no dimmer switches in my office.

The electrician then reached for the light switch by the stairs … and the room lit up brightly. Startled, I asked, “What did you do?” I felt like Homer Simpson when he showed me a tiny gizmo on the side of the light switch that dims the lights when you move it down and makes them brighter when you move it up.

Time elapsed to “fix” the problem: 10 seconds. (Perhaps three minutes if you include the time that passed from the moment the electrician walked though my front door until the moment he departed.) Cost: $96.

I tried to make a case for a less-expensive punishment for my visual-processing deficit, but he let me know that no negotiation was possible. Regardless of the problem or how long it took to “repair” it, the minimum cost for a service call was $96. Period.

I had looked at my office light switch a thousand times in the seven months that I’ve lived in my house, yet had never visually processed that tiny lever on the side. The reason my eyes didn’t process this information is because they were focused only on turning the lights on and off. Thus, the “fact” that there was no dimmer switch in my office wasn’t an illusion, but an assumption based on a lack of concentration on my part.

The Illusion of Deleted Files

But illusions, too, can lead one to make false assumptions. For example, a significant portion of the population still believes that when you delete a file from your computer, it’s no longer there. In fact, it’s only an illusion. When you think you are deleting a file, all you’re really doing is deleting the pointers to that file.

Many have found, to their dismay, that a computer-savvy individual with sophisticated equipment can recover “deleted files” from just about any computer. Which is why it’s a good idea to remove and destroy the hard drive from any computer you discard, sell, or give away.

There are programs that supposedly will wipe your hard drive clean beyond recovery, but the most secure method I’ve found is to physically destroy it. This requires a special set of starburst screwdrivers and an understanding of where all the hidden screws are embedded. Beyond that, it’s much too complicated to explain in detail here.

Likewise, most people infer that when they save a document, it is saved as a complete unit in a single, specific location on the hard drive. Again, this is just an illusion created by the fact that all you see on your computer’s interface is a complete document or file icon. What really happens is that the computer saves the document in fragments to whatever spaces it comes to first on the hard drive.

Who’s on First?

Not long ago, at Oriole Park, I witnessed a graphic example of how illusion and assumption can affect simple, everyday activities. With the Orioles’ Miguel Tejada on first base, Javy Lopez hit a shot to deep left-centerfield that was headed out of the park.

Angels centerfielder Darin Erstad jumped up at the last second and appeared to snatch the ball just before it could land in the stands. He fell to the ground and looked like he was tightly holding onto it. Whether this was by accident or design, just about everyone in the ballpark – including Tejada – inferred that Erstad, based on what they had witnessed, had caught the ball.

So Tejada, who was almost to second base, ran back to first to avoid being caught in a double play. On the way back, Lopez – who apparently did not think Erstad had caught the ball – passed Tejada, who was running in the opposite direction.

Guess what? The centerfielder did not catch the ball. It had gone over the fence. Give Lopez a high score for visual acuity, and send Tejada to a developmental optometrist for a checkup.

Then, things got really weird. The umpire called Lopez out for passing the runner in front of him! That’s right, even though he hit the ball over the fence, he was only credited with a single – a rule I didn’t even know existed. But Tejada was allowed to score. Talk about life not being fair.

So, even though both players were looking right at the play in centerfield, at least one of them was taken in by the illusion that the ball had been caught. The way the centerfielder fell to the ground caused Tejada to assume Erstad had caught the ball.

The Money Illusion

I can’t resist giving one last example, because it’s my favorite illusion: paper money. Though most people haven’t a clue about the reality of paper money (i.e., fiat currency), the fact is that it has no inherent value. So, how is it that all governments in the civilized world succeed in convincing their citizens to use pieces of paper to buy and sell goods and services?

Good question. The value of paper money – which is no longer linked to real money (gold) – is based solely on faith. So long as the vast majority of the population believes that paper money has the value that the government decrees it to have, it will continue to be accepted in day-to-day commerce.

However, whenever that faith is lost – as it has been many times throughout history – people will refuse to accept paper currency in exchange for their goods and services. To the extent that the U.S. government continues to print paper money to meet its obligations to fund wasteful projects and to pay people who do not produce goods or services, the day of reckoning will continue to move ever closer.

Clearly, the value of paper money is an illusion based on faith. As a result, when someone hands the seller of a product or service a $20 bill, that seller assumes that the figure “20” he sees on the bill represents something tangible. Alas, it does not.

The handful of examples I’ve alluded to in this article should make it clear to you that inferences, assumptions, and illusions play a major role in our daily lives. Which is why it’s so important for you to be conscious of the premises upon which you base your inferences and assumptions.

Remember, the world is filled with illusion, and there is a lot more to reality than what we can actually see. By making it a habit to concentrate on what’s going on around you (and especially right in front of your eyes), you are able to swing the odds of success – in all areas of life – in your favor.

“Reality is a sliding door.” – Ralph Waldo Emerson

Robert Ringer

Robert Ringer is a New York Times #1 bestselling author and host of the highly acclaimed Liberty Education Interview Series, which features interviews with top political, economic, and social leaders. He has appeared on Fox News, Fox Business, The Tonight Show, Today, The Dennis Miller Show, Good Morning America, The Lars Larson Show, ABC Nightline, and The Charlie Rose Show, and has been the subject of feature articles in such major publications as Time, People, The Wall Street Journal, Fortune, Barron's, and The New York Times.