The Castle of the Floating Isle

After biking through the mountains of Suruga and sampling the local tea, we made our way back towards downtown Shizuoka, where we would catch the Shinkansen returning us to Tokyo. We were in Japan for a week to celebrate me leaving my job and forming my own company. On the way to the train station, we passed by a tall white tower surrounded on all sides by a moat. A placard identified it as Sunpu Castle, otherwise known as "the castle of the floating isle", and explained that it was built by Tokugawa Ieyasu, perhaps the most significant figure in Japanese history. Born into a samurai family, he rose to power during the late 16th century through a series of cunning political maneuvers and military campaigns. He founded and served as the first shōgun of the Tokugawa shogunate, which lasted for over 250 years.

As I looked down into the water, an amusing thought crossed my mind. I mentioned to my girlfriend that in the world of startups, people often ask what the "moat" of a business is: the thing that makes it consistently defensible and which ideally compounds over time. I dropped a few examples like Instagram's network effects, AWS's economy of scale, and Tesla autopilot's data flywheel.

"It seems like it doesn't make sense to worry about the moat of a business when you're just starting out," she remarked.

"Why's that?" I asked.

"Because it's harder to expand your castle once you've built a moat around it."

Ieyasu didn't construct the castle of the floating isle during his many years of conquest and expansion - it was after he stepped down from the official position of shōgun that he built it, retired to it, and lived out the remainder of his life there.