He has this hypothesis that one of the primary reason for American innovative dominance is due to the ubiquity of basements in America. His theory goes that while much of the rest of the 1st world countries are very crowded in the cities, America has room such that even folks who live in the cities have basements.
Basements being where the majority of the "tinkering" is done, because you don't have to leave home to go work on your pet project. Because basements aren't as "livable" as the rest of the house, they are usually relegated to work benches, mini-offices, and the less-sightly kind of things you wouldn't want sitting out in your living room or cluttering up your closets. And they're as big as the house - so plenty of space to work with.
Because just about everyone has basements, everyone has convenient access to a private working sanctuary to attempt to live out their dreams.
So that's basically how his hypothesis goes. It's one of the more interesting thoughts I've heard, and it's fascinating to see it from the perspective of an outsider who moved here and made something of himself.
Coming from a machinist background (rather than a hacker who can work just about anywhere with a laptop), the availability of a basement for him to keep his machines is something that might seem obvious to him, and certainly lends to why he holds this as true.
Surely it's not the whole truth, but it certainly makes one think.