I picked up a car in Edinburgh and was immediately terrified in the "roundabouts." Cars pouring in from 4 directions, weaving in and out. "Give way to the cars on your right," said Diana, and I used this as a mantra in the roundabouts. I ended up driving the last 2 days in a part of Scotland (near Irvine) that was peppered with roundabouts. Sheesh! I got better with experience, but it was still stressful..
The cabbie on the way to the airport navigated them smoothly, hardly slowed down.
It's such a relief to be back the right (sic) side of the road.