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.
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.