Middle age man walks out of his house and gets into his car. As he prepares himself in the driver seat he turns on his Satellite navigation system and types in his desired destination. He starts the car and sets off.
Satnav: turn left at next junction
The man turns left
Satnav: Drive straight on for 1.3 miles
The man continues driving
Satnav: turn right at next junction.
The man turns right
Satnav: oh……hang on……. it might have been left actually.