My GPS has ESP

Driving in today we were on our way to a routine Doctors visit when I noticed something odd. Our GPS was telling us how many minutes it was to the Doctor's office. This was only strange because I had not told it we were going there before heading to work. Come to think of it the thing normally tells me how far work is in the morning and when I head home from work it tells me how far home is.
How does it know??