My husband and I visited one of his friends once, years ago, when not many people had GPS (the friend had a car with a built-in GPS). The friend was driving us back from his work to his house. After a few minutes, he said, "Okay, I know where I'm going now," and turned off the GPS. Then he got lost. He realized it after a while, turned the GPS back on, and got back on the route. Drove for a bit, then said, "Okay, NOW I know where I'm going," and turned it off again. Then got lost again. Then turned the GPS back on, got himself straightened out, and went to turn it off again. My husband suggested that maybe he should leave it on, just for kicks.
This was a particularly unpleasant drive due to the friend's being one of those people who know there's a brake pedal and a gas pedal, and are pretty sure that you're supposed to be pressing one of them completely down at all times. I was also in the backseat and in the early weeks of pregnancy. So I was rather anxious to have the drive not prolonged.