I also wonder what it means for people who have very poor spatial reasoning. If you have poor navigation skills are you also likely to be bad at memorisation and recall?

I can navigate quite well, but I need to go to where I must make a choice of path. I have a hard time visualizing the map, or the overview, so to speak. I find that I organize my code much the same way. I build patterns that I recognize and can choose the right way (to modify or use) when I get there. I guess it must be the same for everyone, but at different levels of scale.