Like W_D, I learned to navigate--as a youngster--with ancient 30-minute USGS maps and even more inaccurate USFS trail maps. Reading the terrain was really important!

Some modern maps aren't always accurate, either. I remember one area in the Glacier Peak Wilderness where all the maps did not show the trail where it really was. All of us in the party were livid because the maps all showed the trail following a contour, while the actual trail went way, way up, way, way down, up again, and down again. According to the one person in the party who had an altimeter, the actual trail crossed a lot of contour lines!