I was imagining how hard it would be to do in Boston

And yet people did it for 500 years.

Makes you wonder what millions of your predecessors could do that you can't.

Navigate and safely drive at the same time maybe? Which people were presumably not doing 500 years ago. When walking, you're in a lot better position to stop and get your bearings. You're probably also not walking as much to totally unfamiliar areas even if I did get myself a bit lost a few times when I was first in the area.