I get asked all the time, "How did you travel to every country in the world?"
The answer is a complicated one in reality but if I break it down, it really isn't that difficult. There are a few caveats of course. You must have time and money, the two great equalizers of travel. Also, you must have the overwhelming desire to sacrifice to actually do it in order to make this incredible dream happen.
If you have these things then it can happen. Here's how.
1. Research, research, research
I can't stress how important it is to know where you are going, what's around it and how to get between the countries. It sounds simple but some people really don't have a clue about where they're going. Memorize a map, do the research and go to whole regions at a clip. This is how you see multiple countries on one trip. Otherwise you will spend a fortune and take a lot of time to go back and forth many times.
This is especially important in Africa, Central Asia and the Pacific. These destinations require careful planning and knowledge of complex and changing geography, transportation options and border crossings. They operate differently than other easy tourist destinations and have many rules and unexpected things that can happen out of nowhere.
Visas can be the single most annoying thing about trying to visit every country in the world. In Africa, the Middle East and much of Asia visas are a necessity. They are varying in how difficult and expensive they are to obtain. But rest assured, they are a pain and will be costly. I could get into an eternal rant about different countries visa policies but to save you the four letter words, I will just say, know what countries require and do it. You can get this information online at the individual country's embassy website.
Some countries may require doctors notes, AIDS tests, proof of travel, sponsorship, interviews, bank statements, personal declarations of reason for travel or several hand written copies of the same application, among other annoying things.
Unfortunately, there is no getting around these petty requirements and some countries will still make it excessively difficult to get approved or at least take a lot of time. The costs also vary greatly and can run from $20 up to almost $400 for some -- and that doesn't even count expediting or shipping fees, etc. Just be prepared to be frustrated and angered. It's all a part of the process. Developing nations love their bureaucracy and processes. Smile and nod!
3. Have a general plan and know your options
I am the first person to say wing it but in many destinations around the world you need to have at least a general plan. This goes back to research in some ways but you must know the flight schedules, train times or bus options. You must know when and where border crossings close so you don't get stuck in the middle of nowhere.
I never buy flights between countries before I go but I always know approximately which ones I will buy on the ground. I like to remain flexible because you never know what will happen (not everything can be found on the Internet) and long delays/cancellations are inevitable in the developing world. You need flexibility but you need to stay focused on the goal as well.
4. Always carry cash and have access to more money
Many people are scared to carry large amounts of cash on them when they travel, especially in the developing world. To me, this is nonsense. You need cash. Many places do not take anything but cash, and U.S. dollars are king. If you don't believe me, try going to Sub Saharan Africa and try using credit card or travelers checks and tell me how that goes. Also, try finding an ATM in many places; they don't exist and even if they do, your card may not work.
Cash is the way of the world. I always advise carrying a lot of cash in different denominations of bills because there often isn't change where you need it and surely not in dollars. (Note: U.S. $100 bills should always be in good condition and issued after 2006.) There are costs you can never account for and you will have to pay such as tolls, bribes, shakedowns and just general who knows why or what for. It just happens when you travel in the developing world.
If I do a month long overland trip in Africa, then I will generally carry between $2,000 and $3,000 at all times in all sorts of bills. I don't wear one of those money belts or hide in 10 different places. I just keep the cash secure in my pockets at all times. I have never been robbed and always keep my wits about me and am smart about the money. Always project confidence and be street smart. Don't give anyone a reason to want to rob you.
5. Learn the basics in several languages
Language is a big concern for many people and it should be. Knowing the basics in any country you are in can be a huge boost to your experience and your ability to get things accomplished. While it's true that many people speak at least some English in major cities and hotels around the world; that doesn't account for when you're not in the cities and nobody speaks English.
Learn the basics in French, Spanish and Portuguese. This will help you in the Americas, Africa and much of Europe. Also, teach yourself to read Cyrillic. I can't tell you how much easier this has made my life. I can't speak a lick of Russian but I can read the words and this works in much of Eastern Europe, the former Soviet Republics including Central Asia and even Mongolia. Trust me it helps!
I wish I spoke more Arabic but learning the basics of Arabic is a big help and endears you to Arab people. Many will not speak any English but they are very nice people so a few basics will better your experience. Don't be coy; speak to the locals as best you can and they will in turn help you the best they can.
There are obviously many other things that go into traveling to every country in the world but again if you want to achieve this feat, it is possible. You need time and you need money but you don't need to be rich. It is doable but you always need access to money just in case something happens. There's nothing to it but to do it. Set your mind on it and you will be amazed at what you can accomplish.