Apparently you can't even greet someone unless you know the cardinal directions - an article I read in New Scientist claimed that a greeting is essentially telling which direction you came from and in which you are headed.

Be that as it may, I can easily believe that this feature of the language forces you to keep track of directions, after something I experienced: I was always good at keeping track of directions myself, I could walk around in sunless cities for hours and always know which direction I should go to get back to where I started. I could do this while driving too (I also traveled to other countries and drove around in many unfamiliar cities).

But then GPS navigation systems arrived. Convenient, I thought. Until I realized I had completely stopped tracking cardinal directions unconsciously. I haven't used car navigation since that hit me, and it was actually hard to get back into the habit of keeping track of where I am. I'm not sure I will ever again be as good as I used to be.