@gear,
I lived in England from age 13 to 18. We lived "on the economy," off base with the british(father stationed at RAF Alconbury--I also was born in England, RAF Sculthorpe(only there 6 months that time)). Never got a license in the UK, but when we returned stateside, I had to constantly remember to drive on the right side...never made the error of driving on the left in the states, but I had to think about it until it became second nature.
Well, I hope more use cycling or walking for short shopping trips. I often will use the bike just to pick up a prescription or go to the bank instead of using the car.