In his former office at Google, overlooking the San Francisco waterfront, John Hanke kept the shelves well stocked with games. Computer games, as befits a man obsessed with technology, but proper, old-fashioned board games too.
Prominent among them were Risk, Settlers of Catan and Stratego. All three have the same simple aim: to take over the world.
Today, the 49-year-old Hanke can lean back in his new office chair a few blocks down and put his feet up. With the help of a small group of visionaries including a Japanese computer game wizard and a British advertising guru, Hanke's digital start-up Niantic has delivered the phenomenon that is Pokemon Go. Global domination is complete.
Briefly, for those few readers still unfamiliar with the smartphone game, Pokemon Go users walk around streets chasing and capturing cartoon monsters that appear in real locations on their phones. In the first week of release it became the fastest-growing mobile game of all time, and has now hit more than 30 million downloads. Nintendo, the Japanese-based game maker which has an unquantified stake in Niantic and owns one third of the Pokemon series, has seen its market value more than double to 32 billion ($60b) in a single week.
Since its release, rescue teams in Britain have been called out for teenagers stumbling across train lines, into caves and even into a lake in pursuit of these rare virtual characters. Servers have crumpled under the demand.
The spark of genius behind this success story is to be found in Japan, where the famously reclusive computer developer Satoshi Tajiri invented Pokemon back in 1990. Originally launched on the Nintendo Game Boy, Pokemon became a huge gaming, television and film franchise.
In one of his rare interviews, given in 1999, Tajiri said he came up with the idea after obsessively catching insects when he was a child growing up in the western Tokyo suburb of Machida: "I think a lot about kids and what they need and want to make their lives better." Now aged 50 and worth an estimated US$5.1b ($7.3b), Tajiri continues to work on Pokemon in Japan and retains his boyish looks despite a punishing schedule of 24 hours' work and 12 hours' sleep.
Hanke enjoys a more public persona in Silicon Valley, though he too values his privacy. He is married with three children but keeps his family out of the limelight.
Those who know him speak of the man who hails from Texas as a true innovator. Perhaps, even, the next digital entrepreneur to follow in the footsteps of Apple founder Steve Jobs. "John Hanke is an absolute genius," says David Jones, the only British investor with a stake in Niantic.
Last November, Jones joined a few other Silicon Valley investors who backed the company as part of its first $5 million funding round. While he won't say how much he has invested or how much he stands to gain, he adds: "It's pretty fair to say, anybody who invested would have done well."
A high-flying entrepreneur, Jones says Hanke "is a visionary in that he understands not just where the future is going but creates the things that will change that future. We're all talking about Pokemon Go but in reality a whole new world has just been created."
Pokemon Go is not the first time Hanke has reinvented our reality. At the turn of the millennium, the former United States government worker founded the digital mapping firm Keyhole, which was bought by Google and turned into the game-changing Google Maps, released in 2005.
Hanke remained at Google for another decade, initially launching Niantic within its fold before setting up as an independent company in October last year with $30 million investment from the Pokemon Company, Google and Nintendo.
"He's one of those really smart guys who can be quite hard to speak to," says Steve Peters, a 55-year-old designer who worked with Hanke at Niantic prior to the split from Google.
"A lot of Mensa-level geniuses at Google are like that. He's eccentric, in a good way.
"He's stuck by that vision that the world is a great place to be present in, not behind a computer screen. It's a very noble cause."