Roundabouts feel intuitive until a question adds a vehicle already circulating and one entering at the same moment, and suddenly the "obvious" answer isn't so obvious.
Here is one worth locking in:
If you are already on a roundabout, do vehicles entering it need to give way to you, or is it the other way around?
Vehicles already on the roundabout have priority, entering traffic must give way, even if the entering vehicle is on what feels like a "bigger" road. Learners sometimes reverse this because they default to "right of way from the right," which does not directly apply once you're inside a roundabout.
Beyond entering priority, this category also covers lane discipline while circulating and when you're expected to signal your exit.
Your turn. If there is a roundabout scenario you keep mixing up, post it here. If you know the answer to someone else's, help them out.