One of the perennial debates I’ve had with frequent travelers is over how to count the total number of countries visited. Do you count layovers? What about driving or riding a train through a country or state without getting out? Do you have to eat a meal there? Spend a night there? Have at least one interaction with a local in that place?

Then you have more difficult, political questions: What counts as a country? I personally count Tibet, Hong Kong, Puerto Rico, and Scotland as separate countries on my list, but that might be because I measure my self-worth in souvenir flagownership. CGP Grey, YouTube’s resident map extraordinaire, has tried to answer the question, “How many countries are there?” and has come up with several answers. Taiwan, for example, is not considered a separate country by a few important entities (like, ahem, the Communist Party of China), nor is Kosovo, Palestine, or Somaliland. But their people see them as separate, and they are all autonomously governed, to varying degrees. As CGP Grey says, “Ultimately, what makes a country a country is that other countries think that country is a country.”

So we still don’t have a definitive answer. What criteria do you use?