American cars

I've had a little bit of trouble with American roads.

Mostly I'm fine but every here and there I have to stop and think about what I'm doing. Usually this is a problem when I'm out walking, say with the dogs, or running. I can't quite remember which side I should be on, where cars will be coming from, or how to cross the street. It's not instinctual, I have to give it conscious thought.

That doesn't surprise me; though I didn't drive in Scotland, and never adapted to driving on the left-side of the road, I'm definitely used to being a pedestrian in such situations.

However, I have since noticed a little trouble driving. Not always, but in strange situations.
Case in point.
I went shopping the other day and was driving (in the right lane) in the parking lot towards a space I wanted. Another car ahead of me, coming towards me, was in to my lane, presumably to make the wide left and snag the same space.
But for a few moments I stared blankly at the car head-to-head with my own. My mind raced. What country am I in? What side of the road am I on? What side of the road am I meant to be on?
And finally, So, if I'm in America, then why is he in my lane?

Too late. My parking spot was gone.