Driving in Japan with the wheel on the right side. The first time I did that last year I drove on the wrong side of the road about 5 times and got a shock every time when I saw all the ghost drivers just to quickly realize that it's me who is driving the wrong way. This year it only happened one time, so my brain seems to adapt to that better and better.
I once took a trip to the UK and was brave enough (or dumb enough) to rent a car in London and drive around the country side. I drove down small town streets the wrong way several times and I nearly killed myself trying to navigate a roundabout twice.
As a passenger it was frightening. You sit there in what has always been the drivers seat to you yet you have no control over the vehicle.
Hmm, what do you have against roundabouts? They are usually seen as a safer and more efficient type of intersection in most scenarios as compared to traffic lights.
I'm in the same boat! It's a tough transition after driving on the right my entire life. Luckily my wife is always in the passenger seat and will remind me on every turn with "SHARP LEFT" or "WIDE RIGHT". It helps me immensely.
Even in countries that have been historically dominated by manual transmissions, they're starting to disappear. Where efficiency was once their main selling point, most modern automatic transmissions can do it better. Sure takes the fun out of it though.