Holidays are good for you. Aren’t they?

There’s a glass wall in Dublin Airport that separates departing crowds from those that have just arrived. On one side people walk or run towards their gates. On the other people with colourful crumpled clothes amble towards the arrivals hall.

Imagine a time kink where you could see yourself on the other side of the glass heading for the departure gate. If you could hold up a sign to that preholiday self what would it say? “Don’t check emails” or even “Turn back now.”

At the peak of suncream season, it is time to ask if holidays are even good for us. We have been urged to work on getting a holiday body for years. We think about holiday wardrobes, holiday playlists, holiday reading. But what about our holiday heads? Are there tricks to avoid feeling vaguely anxious and regretful at the end of what are supposed to be the best two weeks of the year?

The bad news is that human nature may not be suited to holidays. In 1997 American psychologists asked people to fill out “emotional inventories” before, during and after their trips. The results were a little bleak. Everyone was least happy about the holiday when they were actually on it, battling the logistical snarls of travel and feeling under pressure to enjoy themselves. They were happier before their holiday, anticipating it, and afterwards, remembering it fondly.

The British philosopher Julian Baggini agrees with this research. “I think the two main pitfalls of holidays are collecting memories and ticking off experiences. Both take us outside of the experience itself.” He describes himself as a “sight sceptic”. “More often or not, visiting a famous tourist spot is a disappointment. It is often better simply to wander around an interesting area, soak things up and stumble across something perhaps modest but unexpected. That’s also why over-reliance on guide books and apps is distracting.”

The psychiatrist Conor Farren, who wrote The U-Turn: A Guide to Happiness, is on holiday when I ask for his view on this subject. He sends me a text. "People can often regard holidays as total freedom from responsibility and act accordingly. A lot of alcoholics can relapse on holidays. If the holidays are too long and too relaxing, the return can be a real shock and adjustment a bit difficult."

We are more Berlin than Boston in our approach to longer holidays. EU countries take an average of 34 paid days holidays a year, compared with 25 in the US. Americans have become even more holidayphobic. The always-working culture has never been stronger. This year a study found that four out of 10 Americans do not take an average of eight days of their already limited holiday time, effectively leaving a million years of untaken leave on the tables of US employers every year.

“We can train ourselves to getting used to any length of holidays,” Farren says. “Americans can convince themselves that two weeks per year is enough, and teachers convince themselves that three months is too little.”

Sally Maguire is a secondary-school teacher and the outgoing president of the Association of Secondary Teachers of Ireland (ASTI). She says she has always meant to take a photograph of her teaching colleagues in June and then again in September, to show the physical difference between preholiday and postholiday teachers. “We spend the first two months getting over the stress of the end of year.” A lot of teachers work during the holidays, she says, because 35 per cent of secondary teachers are part-time or temporary teachers.

For those who take their holidays, can it be unsettling to come back to the classroom after such a long break? “It takes a bit of getting used to, but usually after two days you wonder, Was I ever away?”

It is a different scenario for the self-employed and, particularly, those in the hospitality industry, where holiday time is typically their busiest.

Michelle Darmody, owner of the Cake Cafe and Slice, in Dublin, never goes on holiday during the traditional summer months. “November and January are my holiday times. Last November we went to California for two and a half weeks. This November we’re going to Oman and Istanbul,” she says. “I think it’s absolutely necessary to get that break. Running a business is very hard on a day-to-day basis, and when you can get the concept of not thinking about it for a while you come back re-energised. I usually come back with a list of things I want to do.”