There are many popular pirate myths which are more common in fiction than in reality. Here we will try to extract some facts from fiction.
According to popular conception, walking the plank was a method of murder or torture pirates used. The victim was forced to walk off the end of a wooden plank that is attached to pirate ship. After that, victim was forced to fall into the water to drown or feed the sharks (which would often follow ships).
Despite its popularity in fiction works, pirates rarely used this method for disposing captured cavils and enemies. They used the simplest ones, maroon or kill.
Did pirates really say "arrrrr"? They probably have their own slang and phrase but slang we know came out of Hollywood, not from real pirates. Particularly "arrr" and some other popular pirate phrases originated with Robert Newton, the actor who played Long John Silver in many classic movies.
There is a myth that pirates buried enormous quantity of stolen goods and gold in some remote places, usually deserted islands, which they can be found only by treasure maps they created.
Reality is that buried treasures were uncommon and treasures maps ware rare among real pirates. In fact pirates who buried their treasure were well known for that, like Captain Kidd and Francis Drake. Pirates knew their average lifespan is short so they spent their money as soon as they could, mostly on fun.
Text above is usual description of pirate in today’s fiction (ok, probably with some of mentioned elements, not all of them). Some of these features were in fact a very common and useful to real pirates.
Pirates and especially pirate captains almost always had nicknames. They hid real name as they tried to prevent officials from finding their families at their hometowns.
Although they kept some exotic animals (usually for trade purpose, not as pets), real pirates didn’t have parrots, especially on their shoulder as Treasure Island’s Long John Silver.
Eye patch, a small patch that is worn in front of one eye, usually to cover a lost or injured eye, is probably most stereotypical feature of pirates. In fact, they were also very practical to real pirates as eye patch kept one eye adjusted to the darkness below decks.
Peg leg - an artificial limb of carved wood is also often seen on pirates in books and movies. Wooden leg was also used by real pirates considering their profession that included many battles, poor quality of medicine and conditions in which pirates lived.
There are many proofs that the famous Jolly Roger flag was flown by many pirates. Their famous tactic of luring prey by flying the national flag and then switching it with Jolly Roger when they were close enough to capture them is well documented.