Why does Reykjavik build a wall to separate itself from Iceland?

To keep back the sea, perhaps. On an island, this may be the way: one is always blocked by water. It can be comforting. As things evolve, however, blocking behaviour become internalized, and then when your colonizers give you cars, why, you can always drive around, right? There remains no price for blocking … or does there? Or does “driving around” still not untie an old, old knot?