I noticed this the first time I took a walk by myself to the town center rather than letting my parents drive me there. You know the routine: drive to the mall parking lot, go and get the thing you're looking for, drive home. Well, I didn't have my own car and figured I could walk there (about an hour, so probably 2-3km, in a country that uses sidewalks). It's basically magical how much stuff you notice that you would just ignore when in the car, even as a passenger.