In school, we quickly learned that all lessons are not taught by teachers or found in textbooks.

This includes learning the ins and outs of a one-finger gesture that in the old days might earn you a visit from “Officer Friendly.”

As a boy, older kids would often “give the finger” to others during schoolyard arguments. People would get mad. We thought it meant something “dirty.”

Once, I was embarrassed when a little nun pulled me into a corner and asked about “the finger.” I couldn’t tell her it was a symbol of “something dirty.” So, I just said it was a way of showing contempt. She seemed to accept that answer, although I’ll bet she knew better.

But what does it really mean? Where did it come from? Was it something that was invented in the 1940s in our schoolyard? 

One of the things I like about the age we all live in is the ability to sit down at a computer and find out lots of interesting stuff.

So I Googled: “the finger,” and got a lot more information than I needed for this column.

In a BBC magazine post from 2012, “the finger” was described as “a public intellectual expression of contempt for a gas-bag politician.”

The post and others claim it is an ancient insult going back to 4th century BC when a Greek philosopher named Diogenes extended his middle finger as he told a group of visitors what he thought of the orator Demosthenes. In ancient Rome, it was known as “digitus impudicus,” the shameless, indecent or offensive finger.

But “the finger” might get you in trouble. For example, I learned a British motorist was photographed “flipping the bird” at a traffic camera. Reuters reported he was arrested and jailed for eight months.

In Indiana, Newsweek told me that when a state trooper swerved in front of his car, a motorist showed his displeasure by waving his middle finger at the lawman. He was arrested for “provocation,” and convicted, but the offense was vacated on appeal.

Twelve years ago, in the city of St. Johnsville, New York, a small town located in the Mohawk River valley,  a man named John Swartz was riding through town when he saw a local policeman monitoring traffic with a radar gun. Swartz showed his displeasure at the law officer by “reaching his arm out the window of the passenger side and extending his middle finger over the car’s roof,” according to court documents. That gesture led to his jailing, but a federal appeals court later ruled the “ancient gesture” was not grounds for arrest.

Once upon a time, way back in the 1960s, I loved a popular TV program called “Laugh-In.” A feature of that comedy show was an award dubbed “The Flying Fickle Finger of Fate.” It was given to an individual or government agency that had done something outrageous or silly.

Search the internet and you will find lots of photos of the “bird.”

In 1886, a photo of the Boston Beaneaters baseball team shows a pitcher named Charles "Old Hoss" Radbourn with an extended middle finger. They suggest he was flashing it towards the team’s national league rival, the New York Giants.

In 1976, a famous photo shows Vice President Nelson Rockefeller “giving the bird” to a group of anti-Vietnam War protesters who were interrupting a speech he was giving in Binghamton, New York. The same photo shows Sen. Bob Dole (R-Kansas) laughing at the Veep.

Recent photos showed former Congressman Anthony Weiner flashing “the bird” at photographers after he lost his job for texting nude “selfies” to a woman.

Recently, press photos showed a woman giving “the finger” to a presidential motorcade. She lost her job.

My all-time favorite “bird” story happened in 1968, after North Korean armed forces captured a U.S. Navy ship, the USS Pueblo, and jailed its crew.

Later, after being accused of torturing the American sailors, North Korean officials cleaned up the crew and trotted them out for a photo to show that they were being fed and treated well. The sailors, who knew they were being used for propaganda purposes, went along with the gag. After all, it was a chance for them to get some good food, a shower, and some clean clothes. But, in an act of defiance, as they smiled for the camera,  many extended their middle fingers.

When their captors asked about the gesture, the sailors claimed it was a Hawaiian good luck symbol. Sure it was.

What about here? Will Boothbay Harbor police lock you up if you show disdain for the law with the gesture known as “the finger?”

“No,” said Chief Robert Hasch with a laugh. “It is protected free speech. We have to have a tougher skin than that.”