Pub Etiquette
The crucial thing with pub etiquette 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, where after it will attach to your offspring and possibly theirs as well. In some cases, it may become permanently enshrined in a family nickname.
Ireland has two time zones:
(1) Greenwich Mean Time and (2) "Local" time. Local time can be anything between ten minutes and three days behind GMT, depending on the position of the earth and the whereabouts of whoever has the keys. 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 premise 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.
Woolly Jumpers
Ireland produces vast quantities of woollen knitwear and, under a US/Irish trade agreement, American visitors may not leave without a minimum of two sweaters, of which one at least must be the ubiquitous "green woolly jumper". Airline staff may check that you have the required documentation before you are allowed to disembark. Continental (that's Europe, not the airline) visitors are only required to have one woolly jumper, but must have a copy of "The Collected Works of Seamus Heaney" as well.
Irish Traditional Music
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.
Irish People and the Weather
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.
Irish Dancing
There are two main kinds of Irish dancing: (1) Riverdance, which is now simultaneously running in every major city except Ulan Batar and which some economists believe is responsible for the Irish economic boom; (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.
Clothes
Visitors to Ireland in mid-March often ask: What clothes should I bring? The answer is: All of them!
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 soccer team. It's possible that green just doesn't suit the Irish skin colour, which is generally pale blue.
Gaelic Games
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 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. (In other words, camogie is played by girls - ed.) (Well, they wear skirts and have long hair - ed again.)
Schools rugby
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.
Signposting
In most countries, road signs are used to help motorists get from one place to another. In Ireland, it's not so simple. Signposting 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.
Religion
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 straight away and sit with your feet situated flat on the floor.