The crucial thing here is the "round" system, in which each participant takes turns to "shout" an order. To the outsider, this may appear casual; you will not necessarily be told it's your round and other participants may appear only too happy to substitute for you. But make no mistake, your failure to "put your hand in your pocket" will be noticed. People will mention it the moment you leave the room. The reputation will follow you to the grave, whereafter it will attach to your offspring and possibly theirs as well. In some cases, it may become permanently enshrined in a family nickname.

Ireland produces vast quantities of woolen knitwear and, under a US/Irish trade agreement, American visitors may not return to the States without a minimum of two sweaters, of which one at least must be predominantly green. Airline staff may check that you have the required documentation before you are allowed to disembark. Note: under no circumstances will you see an Irish person wearing a woolen jumper. These jumpers are worn solely by Americans to identify them to muggers, thieves and knackers.

It is often said that the Irish are a Mediterranean people who only come into their own when the sun shines on consecutive days (which it last did around the time of St Patrick). For this reason, Irish people dress for conditions in Palermo rather than Dublin; and it is not unusual in March to see young people sipping cool beer outside city pubs and cafes enjoying the air and the soft caress of hailstones on their skin. The Irish attitude to weather is the ultimate triumph of optimism over experience: Every time it rains, we look up at the sky and are shocked and betrayed. Then we go out and buy a new umbrella.

Local time can be anything between ten minutes and three days behind GMT, depending on the position of the earth and the where abouts of the man with the keys to the hall. Again, the Irish concept of time has been influenced by the thinking of 20th century physicists, who hold that it can only be measured by reference to another body and can even be affected by factors like acceleration. For instance, a policeman entering a licensed premises in rural Ireland late at night is a good example of another body from whom it can be reliably inferred that it is fact closing time. When this happens, acceleration is the advised option. Shockingly, the relativity argument is still not accepted as a valid defence in the Irish courts.

Many visitors to Ireland make the mistake of thinking of traditional music as mere entertainment. In some parts of Ireland this may even be an accurate impression. However, in certain fundamentalist strongholds such as Clare, traditional music is founded in a strict belief system which has been handed on from generation to generation. This is overseen by bearded holy men, sometimes called "Mullahs", who ensure that the music is played in accordance with laws laid down in the 5th century. Under this system, "bodhran players" are required to cover their faces in public. Other transgressions, such as attempting to play guitar in a traditional session, are punishable by the loss of one or both hands. A blind eye may be turned to the misbehaviour of foreigners, but it's best not to push it.

There are two main kinds of Irish dancing: (1) Riverdance , which is now simultaneously running in every major city in the world except Ulan Bator, and which some economists believe is responsible for the Irish economic boom; and (2) real Irish dancing, in which men do not wear frilly blouses and you still may not express yourself, except in a written note to the adjudicators.

Strangely enough, Irish people tend to wear everything except green, which is associated with too many national tragedies, including 1798, the Famine and the current Irish rugby team. It's possible that green just doesn't suit the Irish skin colour, which is generally pale blue (see Weather).

St Patrick's Day brings the climax of the club championships in Gaelic games, which combine elements of the American sports of gridiron and baseball but are played with an intensity more commonly associated with Mafia turf wars. The two main games are "football" and "hurling", the chief difference being that in football, the fights are unarmed. There is also "camogie," which is like hurling, except that in fights the hair may be pulled as well.

St Patrick's Day also brings the finals in schools rugby, a game based around the skills of wrestling, kicking, gouging, ear-biting, and assaults on other vulnerable body parts. The game is much prized in Ireland's better schools, where it's seen as an ideal grounding for careers in business and the law.

It is well-known that St Patrick banished the snakes from Ireland. Less publicised is that he also banished kangaroos, polar bears and Vietnamese pot-bellied pigs, all of which were regarded as nuisances by the early Irish Christians.

In most countries, road signs are used to help motorists get from on place to another. In Ireland, it's not so simple. Sign-posting here is heavily influenced by Einstein's theories (either that or the other way round) of space/time, and works on the basis that there is no fixed reference point in the universe, or not west of Mullingar anyway. Instead, location and distance may be different for every observer and, frequently, for neighbouring road-signs.

Ireland is officially bilingual, a fact which is reflected in the road-signs. This allows you to get lost in both Irish and English.

Visitors to Ireland in mid-March often ask: What clothes should I bring? The answer is: All of them!

Ireland remains a deeply religious country, with the two main denominations being "us" and "them". In the unlikely event you are asked which group you belong to, the correct answer is: "I'm an atheist, thank God". Then change the subject.

For all you foreigners out there - take note of Pub etiquette in particular.