I have no trouble with the "big picture" and navigating to any destination by bike or car, based the map in my head. However, sometimes I set out on a long rec ride across the city specifically intending to link a series of ravine trails and power corridor paths and so on, that have limited access points to city streets, and I have to periodically check the city bike map to make sure I haven't missed a connection. See eg.
http://www1.toronto.ca/City%20Of%20T...gMap_tile7.png