It's basically just an innately good sense of dead reckoning. I was especially good at it growing up in Chicago where pretty much every street is either N/S or

It's basically just an innately good sense of dead reckoning. I was especially good at it growing up in Chicago where pretty much every street is either N/S or E/W, it made it much easier. You just needed an intuition of the difference between your left turns and right turns, or you could just explicitly count it.