I've made the switch! I now drive on the left, in a manual car that has a stick shift on the left. It was daunting at first. The hardest part about learning to drive confidently on the left is relearning one's deeply ingrained instincts. The car mirrors aren't where I'm used to. Looking over my left shoulder when I'm backing up doesn't feel natural. And passing on the right just seems weird. The other hard part is knowing which lane to be in. Most intersections here are round-abouts, some with several spokes that branch out from the circle. I'll admit I've circled around a few round-abouts more than once, trying to get into the right light for the spoke that I want.
I have a new best friend to help me with the driving. I haven't named her yet, but she has a lovely accent and is very patient with my when I miss her instructions and take the wrong turn. She's called a Sat Nav here, and a GPS in the U.S. I used to listen to NPR every time I drove somewhere in the U.S. Here I listen to a voice telling me that there is a round-about in 300 yard and that I want to take the 3rd exit in the roundabout.
Why do the English drive on the left?
In the Middle Ages you kept to the left for the simple reason that you never knew who you'd meet on the road in those days. You wanted to make sure that a stranger passed on the right so you could go for your sword in case he proved unfriendly.
This custom was given official sanction in 1300 AD, when Pope Boniface VIII invented the modern science of traffic control by declaring that pilgrims headed to Rome should keep left.
The papal system prevailed until the late 1700s, when teamsters in the United States and France began hauling farm products in big wagons pulled by several pairs of horses.
These wagons had no driver's seat. Instead the driver sat on the left rear horse, so he could keep his right arm free to lash the team.
Since you were sitting on the left, naturally you wanted everybody to pass on the left so you could look down and make sure you kept clear of the other guy's wheels. Ergo, you kept to the right side of the road.
The first known keep-right law in the U.S. was enacted in Pennsylvania in 1792, and in the ensuing years many states and Canadian provinces followed suit.
In France the keep-right custom was established in much the same way. An added impetus was that, this being the era of the French Revolution and all, people figured, hey, no pope is gonna tell ME what to do.
Later Napoleon enforced the keep-right rule in all countries occupied by his armies. The custom endured even after the empire was destroyed.