The first time I used Google earth, most parts of Uyo (a small town in AkwaIbom State, Nigeria) was not yet covered, each time I tried, it will show a picture of a clouded area, gradually it got more vivid pictures of my town and now I can use it for a lot of purposes...
About depending on the map for direction, one day my app was telling me calibration error and was not calibrating, I used it to travel and it mislead me.