If life has taught me anything it’s that P.T. Barnum was wrong when he said, “There’s a sucker born every minute.”

It’s more like every second.

Frankly, I’m amazed at what people will believe, especially if the backstory seems reasonable (or, perhaps more accurately, not entirely unreasonable) and the source is judged to be sane (or, perhaps more accurately, not entirely insane).

For example, today I heard a guy who fancies himself a top horse handicapper insist that one should be on the lookout for horses with the word “ghost” in their name.

“If you see a horse with ‘ghost’ in its name you may want to pay a little bit of attention to that,” he said enthusiastically. “Usually those ‘ghost’ horses — they give the name ghost to a horse for a reason — usually, it’s lightning fast.”

Huh? Says who?

Certainly not any data that I’ve seen.

In fact, a quick perusal of my database revealed that ‘ghost’ horses produced a -61.3% ROI at various North American racetracks from 2013 to 2019. So, yeah, I guess they are “lightning fast” — at separating you from your bankroll. (In fairness, the sample size was very small, but I don’t expect the red ink to subside anytime soon.)

Look, I’m not trying to make fun of this guy, specifically; frankly, I witness this kind of “thinking” all the time. Have you seen the new face masks designed for singers and musicians? They’re akin to reading glasses without lenses — only not as effective (see below).

Truth is not arbitrary, nor is it derived by consensus. Just because “everybody” believes something to be fact doesn’t make it so. That’s why I love sports gambling and investing in the stock market — they allow rational speculators to profit on goofy ideas held by the masses.

Take, for example, the notion of “revenge” games in the National Football League.

There is a belief, held by many, that a team coming off a blowout loss against a division rival will be more motivated the next time the two squads face off — you know, to get “revenge” on their opponent (as though winning, in and of itself, is not enough).

So, does this make sense? Well, not if you want to make cents.

I looked at eight prolific NFL teams from each division — Dallas, Green Bay, Seattle and New Orleans in the NFC; Pittsburgh, Denver, New England and Indianapolis in the AFC. With the exception of New Orleans — sorry, Saints fans — all had won at least one Super Bowl, and all had winning records over the past decade.

Then, with the help of sportsbettingstats.com, I tallied their results against division rivals when coming off a win or loss by 15 points or more (since 2005).

If the revenge theory is true, a blowout win should be followed by an against-the-spread loss, while a blowout loss should be proceeded by an ATS win.

Yet, this only happened 50.9% of the time — good for a loss of 2.7 cents per dollar wagered.

In another study relating to revenge, published in 2012, the National Football Post examined “every playoff loss since 2001 and then checked to see if those two teams met again the following season.”

If they did, the website tallied the results, which were underwhelming to say the least. While the teams out for revenge did win 37 of the 67 games (55.2%), they were just 30-32-5 ATS, producing a loss of 7.6%.

Apparently, revenge is not the huge motivator many believe it to be.

The bottom line is this: Don’t accept theories without supporting data — and, even then, be skeptical. Many promising analytical models have been built on unsubstantial samples, or tainted by bias in the setup and execution of the studies promoting them.

As always, caveat emptor!