...you were only allowed to travel to one country in your lifetime?

Imagine you were only allowed to visit one country. You can pick what country you would like to travel to and you can stay there up to one whole year. However, once you return to your hometown you have to remain there for the rest of your life.
Where would your destination be?

If everyone chooses to visit the popular and touristic countries than these would become very crowded. The risk of loosing their calm nature and culture which makes the country so special would increase.
 Furthermore, there might be countries that hardly no one wants to visit, as you can only choose to visit one country. These countries would lose their tourism section and would suffer from a huge financial loss.
Another aspect to consider is when the best time would be to start your trip. Most people would probably decide to departure during the summer months. However, this means that you will have to expect that during this period of time most countries will be full with tourists. The chance of arriving in a less crowded country is bigger if you decide to go traveling during the winter months.
 Since you are only allowed to travel once in your lifetime it would make sense to make the most out of it and spend an entire year abroad. In addition, you would eliminate the question of what time of the year would be the best to go traveling.
Another aspect to consider is at what stage of your life you want to begin your journey. Would you prefer to go while you are still young and full of energy or rather when you have retired and have enough time and money to spend.
All in all if this rule existed it would limit us in many ways. It would be harder to get to know new cultures, languages and people with other ethnicity. This would result in a huge loss of the diversity that our world offers.