1. The quietness of a crowded train

One of the first impressions may be the relative quietness of Japanese public transport.

A train can be full of people and yet remain remarkably calm. Passengers read, look at their phones, talk quietly or simply sit.

Phone conversations on trains are generally avoided, and there is an awareness that the carriage is a shared space.

It is not silence. It is something subtler — a consideration for the people around you.

2. The order of everyday life

Japan has a remarkable ability to organise large numbers of people.

There are queues for trains, buses, restaurants and shops. Railway platforms often have clearly marked positions showing where passengers should wait.

When a train arrives, passengers generally allow those leaving the train to get off before boarding.

After a while, the system becomes almost invisible. You simply join in.

3. Clean streets and very few bins

One of the curious things about Japan is the combination of exceptionally clean public spaces and a relative shortage of public rubbish bins.

You may find yourself carrying an empty bottle or food wrapper for some time before finding somewhere appropriate to dispose of it.

It takes a little adjustment.

It also makes you more aware of the idea that keeping a public space clean is partly a shared responsibility.

4. The frequency with which shoes come off

Removing your shoes before entering a Japanese home is well known.

What may be less expected is how often the same principle appears elsewhere.

Traditional accommodation, some restaurants, temples and other buildings may have a designated place for shoes.

At a ryokan, removing your shoes becomes part of the transition from the outside world into the traditional interior.

Usually, the surroundings give you the answer. Look at what everyone else is doing.

5. The Japanese toilet

The Japanese toilet has become almost a cultural curiosity in its own right.

Heated seats, washing functions, adjustable water pressure and a collection of controls can make a simple visit surprisingly sophisticated.

Some controls are less obvious than others.

A sensible approach is to take a moment to look at the symbols before experimenting.

It is also worth knowing that some toilet control panels include an emergency alarm, so it pays to know which button you are pressing.

6. The remarkable convenience store

A Japanese convenience store, or konbini, is much more than a place to buy a drink.

Food, coffee, snacks, ATMs and various everyday services can all be found under one roof.

The food itself can be an enjoyable discovery.

A convenience-store breakfast may become part of a day's travel, particularly when setting off early for a train or heading somewhere without many restaurants.

The phrase "just popping into the convenience store" can acquire a very different meaning in Japan.

7. Vending machines become part of the landscape

Vending machines are everywhere.

At first they attract attention.

After several days, they become part of the scenery.

Then, perhaps, you notice one in a surprisingly remote location and remember just how ubiquitous they are.

Drinks are the obvious example, but the variety and distribution of vending machines is one of those small details that helps make Japan feel distinctly different.

8. Cash still has a place

Japan is one of the world's most technologically advanced countries, yet cash remains useful.

Electronic payments and cards are increasingly common, particularly in larger cities, but smaller businesses and some rural establishments may still prefer cash.

It is worth carrying some Japanese yen.

There is also the small matter of coins. Before long, your pockets can contain a surprisingly impressive collection.

A coin purse starts to seem like a very sensible piece of travel equipment.

9. Small restaurants can be memorable

Some of the best meals may come from somewhere that looks almost insignificant.

A handful of seats. A small kitchen. A short menu. Perhaps one speciality prepared exceptionally well.

Ramen, soba, yakitori, tempura or a simple set meal can all become memorable experiences.

There is something appealing about a restaurant that has concentrated on doing one thing well.

10. The care given to ordinary things

One of the most noticeable aspects of Japanese life is the attention given to presentation.

Food is arranged carefully. Purchases are wrapped beautifully. Shop displays change with the seasons. Packaging can be remarkably attractive.

A hotel room may contain a small detail that seems unnecessary until you realise it has been carefully considered.

The effect is rarely about extravagance.

It is more about care and attention.

11. Railway stations are places in their own right

A railway station in Japan may be far more than a place to catch a train.

Large stations contain restaurants, cafés, shops, food halls, convenience stores, underground shopping areas and connections to department stores.

Some are almost cities beneath a roof.

And then there is the challenge of finding your platform.

The Japanese railway system is wonderfully efficient, but a large station can still take some navigating.

12. Old and new live comfortably together

A centuries-old temple can sit within a modern city.

A traditional wooden building can stand beside a contemporary apartment block.

An ancient shrine can be only a short walk from a railway station or convenience store.

Japan often makes little distinction between its past and present.

The old does not necessarily have to be preserved in a separate historical quarter. It remains part of everyday life.

That juxtaposition can be one of the most fascinating aspects of travelling through the country.

13. The thoughtful use of small spaces

This may be particularly noticeable to anyone interested in design.

Space can be limited, especially in Japan's larger cities, yet small spaces are often carefully composed.

A narrow entrance. A compact restaurant. A tiny courtyard. A small garden. A shop occupying only a few square metres.

Rather than simply trying to make a small space appear larger, there is often a sense of making the available space feel complete.

It is an interesting lesson in design.

14. Efficiency and slowness exist together

Japan can be exceptionally efficient.

Trains run to precise schedules. Stations handle enormous numbers of people. Everyday transactions can be quick and organised.

Yet there are also many opportunities to slow down.

A cup of tea. A visit to a temple. A walk through an old neighbourhood. An evening in a ryokan. Time in an onsen. Sitting quietly in a garden.

Japan seems entirely comfortable with both speeds.

15. The seasons appear everywhere

In Britain, we are very aware of the seasons, but in Japan they often appear in a surprisingly wide range of everyday details.

Food changes. Menus change. Flowers and plants become part of displays. Packaging changes. Festivals follow the calendar. Seasonal sweets appear in shops.

The changing season becomes part of the visual and culinary experience of everyday life.

Once you start looking for it, seasonal references seem to be everywhere.

16. Consideration for other people

Many of the observations in this article come back to one underlying idea: consideration.

Keeping conversations quiet. Queueing. Avoiding obstruction. Looking after shared spaces. Being aware of the people around you.

Rather than thinking of Japanese etiquette as a long list of rules, it can be more useful to think about the principle behind many of them.

Other people are sharing this space with you.

That simple thought explains a surprising amount.

17. The extraordinary change when leaving Tokyo

Tokyo is enormous.

The buildings, crowds and railway system can be difficult to comprehend until you experience them first-hand.

Then you travel away from the city.

Suddenly there are mountains, forests, rice fields, small towns, traditional houses and quiet railway stations.

The change can be remarkable.

Japan is far more varied than the image created by its largest cities.

18. The experience of an onsen

An onsen can seem slightly mysterious before your first visit.

The procedure is actually quite straightforward.

You wash thoroughly before entering the bath. You leave your clothes in the changing area. A conventional public onsen is enjoyed without swimwear. Your small towel stays out of the water.

Then you simply soak.

There is no swimming and very little fuss.

An outdoor bath surrounded by mountains, woodland or a carefully designed garden can make the experience particularly memorable.

19. You begin to observe rather than simply look

At the beginning of a trip, much of your attention is practical.

Which train? Which platform? Where do I pay? Where do I leave my shoes? What does this sign say?

After several days, some of that uncertainty disappears.

You have more time to observe.

How someone enters a shop. How a meal is presented. How a purchase is wrapped. How people move through a station. How a ryokan is arranged. How a garden meets a building.

You begin asking a more interesting question:

Why is it like this?

That is often the point at which travelling becomes much more rewarding.

20. Japan may be different from the Japan you imagined

Perhaps the greatest surprise is how ordinary Japan can be.

There are temples, gardens, sushi, bullet trains, neon signs and spectacular landscapes.

But there is also everyday life.

People going to work. Children going to school. Someone buying breakfast at a convenience store. A commuter asleep on a train. A shopkeeper preparing for the day. An elderly couple visiting a local shrine. Someone sweeping outside their shop. A gardener tending a small patch of ground.

It is this ordinary Japan that may stay with you longest.