The Car Stereo

This has been bothering me for a while now...how you would be driving down a familiar street, music loud enough for you to sing out of tune and no one would even notice, a smile on your face like everything is just working right...you're off to a friend's son's birthday party. This is where it gets weird...the moment you turn into unfamiliar territory and you pull out the visual display of the map in your head (coz men are too good to take down directions on paper), automatically you either turn off the car stereo or turn down the volume. What is it with being lost and music volume? It's as though it obstructs that patch in your brain that shows you the way...hmmmmm *ponders* is it just me or do you guys do that also?