Everyone knows a maphead. Everyone knows someone, or is someone, who studies the atlas with endless fascination. Or goes geocaching on weekends. Or knows world capitals like the back of their hand, or collects vintage maps, or gives directions with unflappable ease, or all of the above. And it’s tempting to approach Ken Jennings’ Maphead: Charting the Wide, Weird World of Geography Wonks and assume that it’s a niche book for map geeks only. But the affable Jennings opens with a charming account of his own atlas-obsessed youth and from there all notions of inaccessibility fade as he becomes a playful tour guide through the titular “wide, weird world” —a role he manages adroitly, balancing his sense of fun with real respect for its inhabitants. Purchased with saved-up allowance as a seven year old, that world atlas, in addition to providing hours of entertainment for a youngster eager to point out how much Wisconsin resembles Tanzania, helped that same youngster find his place in the world when his family moved to Seoul, South Korea, the following year.

Jennings smartly addresses the widely-held notion that Americans don’t know much about geography early on, going straight to the source and interviewing the University of Miami professor behind the infamous 1983 study. Patiently and thoroughly, he walks through the possible reasons for the general public’s geographic illiteracy. And this is where one would expect the author — a record-setting Je0pardy! champion, after all – to firmly divide the well—informed geo-nerds from the vast, cartographically confused majority. Instead, he uses it to bolster his conviction that geography has something to offer for everyone. An undercurrent of inclusiveness runs below the surface of many of the chapters that follow, as he repeatedly makes the case that these geography wonks are just normal people with engaging, if odd, hobbies. Jennings quietly sells the reader on geography, and he is a very good pitchman.

Each chapter of Maphead concerns a facet of geography wonkdom under the heading of an appropriate cartographic term and definition. Starting with Eccentricity, an exploration of what makes a maphead tick, Jennings guides us through everything from Legend, an account of fictional worlds and the maps therein, to Meander, a visit with a club where the members must have visited over 100 countries and other goal-oriented travellers, to Frontier, a survey of the future of cartography through Google Maps, GPS, and beyond. Whether meeting with young geography bee champions or attempting a perplexing map-based road rally called the “St Valentine’s Day Massacre,” Jennings takes what could have in less graceful hands been dull or mocking and imbues it with infectious, palpable excitement.

It’s when Jennings is with his son, though, that he really shines. Dylan is present in the background about half of the time, and interaction between the two makes clear the difficulties inherent in making geography seem appealing to the layperson, let alone a six year old. Jennings was roughly that age when he was sleeping with an atlas under his pillow, he worries that his children aren’t feeling the same affection. When young Dylan takes an interest in geocaching, Ken’s tangible relief is not unfounded, and it’s of a piece with one of the book’s recurring themes — Jennings interviewees describe a great satisfaction in discovering their own compelling, if peculiar interests, and charting the roads they followed in pursuit.  The solo expedition never sounded so enticing.