It's quite hard for other people to understand my 'obsession' for touring cycling. The usual response I get is "Why don't you just take the train?". Other people are more understanding, like hikers and high-speed cyclists. But there is this unique experience about long distance cycling that is especially compelling to me, and it's exactly this experience that is the reason why I like long distance cycling.
Some people assume I cycle for the sport of it. The achievement of doing 100km a day on a road with many uphills on a bicycle loaded with luggage is by no means easy, and I do get a profound sense of satisfaction from being able to accomplish it. I like how cycling makes me lose weight, I like how it makes me fit. But it is by no means the main reason of why I cycle.
The main reason I cycle to places is because I believe that to truly understand a place, you must experience all parts of it, including how to get there, how to navigate there, and how to spend the night there. Cycling gives you the most complete experience of a place. If you're in a car you can't just stop on a bridge to take a photo or enjoy the view, and you'll have tons of trouble finding a parking space in a busy town or city. Walking might work but you'd be too limited in range and amount of luggage you can carry. A fit guy on a touring bike though, can go anywhere and bring with him everything that he could possibly need.
I've traveled with a lot of people both in Japan and Europe, and the vast majority of them don't get this. They don't appreciate the journey. They don't appreciate the points between destinations. They don't take the time to form a mental image in their mind of how two places are connected, how things are related to each other. To them, two towns are just two unrelated towns, and the train ride or bus ride in-between is meant for sleeping. To me, the distance between towns is the most important part. That's the area where you learn about why the towns are where they are, how they were formed, how people used to travel between them in the old days. It's also where you see the most beautiful landscapes.
You can experience a town in any number of ways: by tour bus, train, tram, metro, whatever. You can practice sports in any number of ways too: high-speed cycling, running, hiking, they'll all make you lose weight and make you more fit. But none of those things can make you experience and appreciate an area quite as good as long-distance cycling. The journey is what's most important, and long distance cycling will give you the best journey you could possibly imagine.