That's really interesting! Four way stop junctions always confuse me slightly, but I do find roundabouts quite straightforward. Some parts of the UK call them "islands", but to me "roundabout" does describe it perfectly. I do take the lane, especially with the trailer, and the hardest part is the camber which can mean that I'm setting off (often from a standing start), uphill, on a curve and with an extra 50lbs behind me.

The most difficult one I ever drove is in Swindon. Called the "Magic Roundabout", it comprises 5 mini roundabouts in a circle, and you end up with an outer ring of traffic going one way and an inner ring of traffic going the opposite way. Everyone gives way to the right and somehow it all works. It makes my head hurt though.