We switched from a Citroen to a Ford. On the first long trip we made (over Cairn o' Mount) we hit dense fog on the way back down. I confidently reached down to the right to switch on the fog lights... and the dashboard lights went out... By the time I'd actually found the fogs, we had descended out of the cloud layer.
We have a new car (Motability) every three years, and when you have certain requirements (need room in the boot for a wheelchair and room in the back for kids) you tend to stick to the newer model of what you have. Except that the buggers keep changing the control layout! At one point Ford switched the controls on the steering wheel (volume up/down, trip computer etc) over. All that carefully trained muscle memory rendered useless!