Funnily enough I was having a similar conversation with an old hand at this bushcraft lark, regarding navigation sans GPS, map, compass etc. His opinion was that we all have the ability to work out approximately where we are in relation to our environment. This means we all have an in built facility to navigate through our environment, wich becomes the framework for finding our way in a familiar environment. When we are in an unfamiliar environment we have the same ability but less information from memory, to compare to. It is his belief that our dependence on familiarity is what leads us astray. We think we recognise a bit of landscape, either from false memory or false expectation of what ground will look like. If we put aside the traditional navigation aids (but importantly keep them for backup) we can try and learn how to interpret the environmental data. He particularly uses (and gave me a quick demo) the position of the sun, stars, moon and weather. He had me tearing around the Welsh border using the sun, wind and ridge lines as reference points. I have resolved to get him to show me more.
I'm not saying this is a form of inbuilt GPS like in pigeons, more a different skill set, like using a fire drill or knowing where different wild foods are likely to be found.
Take only memories, leave only footprints, brag about it on facebook!