Insular means "having a narrow view of the world," like insular people who never leave their small town, which enables them to believe that every place in the world is the same and the people are all just like them.

The adjective insular comes from the Latin word insula, which means “island.” Perhaps less so in our current age of technological and relatively easy travel, island life can still be separated from the rest. That's why insular can mean "isolated from," like if you grew up in a big city then visited a rural place, you may be surprised that stores close early. Such an experience will help you expand your insular views.