A simple question BUT it is surprisingly difficult to answer. Why is this? Ask your self what is a country and what is a visit?
Imagine, you have visited England, Wales, Northern Ireland and Scotland. How many countries have you visited? The answer is 1 since these areas are part of the United Kingdom; a country recognised by the United Nations. Some would argue that these are separate countries; Scotland & Wales have their own parliaments but do not issue passports? How about the Channel Islands? They issue their own currency and the official language is French. The Channel Islands are dependent territories of the English Crown so they are not independent. Thus, is a country an area which is an independent state? When one refers to a dictionary one is given two definitions:
As a traveller one would prefer the later definition. Surely this is why one visits a country. If one has said they have visited Russia but seen just Moscow then imagine the culture & geography not experienced.
I could make up a definition that tries to meet the above definition such as a country is defined as a territory which has political autonomy sufficient to allow it to issue and manage it's own currency. The problem with this is it my discretion and few may agree with this. Therefore I have chosen two recognised lists:
As a student I visited Yugoslavia a number of times. Since then it has split into several countries e.g. Slovenia, Croatia and Yugoslavia. The areas I visited cover these new countries, thus, have I visited these countries? Firstly, when answering the question 'how many countries have you visited?' the list of countries referenced are those classed as countries at the time the question is answered. Secondly, an existing country is considered as having been visited if the territory visited was within the current existing country's borders regardless of what the territory was named when visiting.
You land in Dubai and change aircraft; you do not leave the airport. Have you visited Dubai? You are in your couchette and during the night border guards wake you up. The train enters the country and travels through it. Again your woken up by the border guards as you cross the border and leave the country. Have you visited this country? The Zambezi river is the border of Zimbabwe / Zambia; I had my passport stamped for Zambia on the river bank to allow me to canoe the river but I never went further. Have I visited Zambia?
The Travellers' Century Club classifies a visit as if you have touched the territory i.e. if you just changed aircraft at an airport it is a visit. I find this hard to accept. The rule I employ is one must have got off the transport, exited a port and actually experienced the country. This currently reduces my count as compared to the Travellers' Century Club classification by 3 territories.
The Home Page provides the answer to "How many countries have you visited?" for myself. This list is based on the above criteria. Some may disagree with the criteria but as you will now appreciate there is no black and white answer.
OK, so you know how many countries I have visited but why travel? Please see Why Travel? for the answer.