Imagine coming from mainland europe and having to drive on the other side of the road (thus also taking roundabouts the other way round), and then navigating this baby...
The Colchester equivalent better demonstrates this: https://en.wikipedia.org/wiki/Magic_Roundabout_(Colchester)
Personal anecdote: I had to drive around one of these junctions during my driving test
https://www.youhaventlived.com/qblog/2005/QBlog160705A.html
There are lights to make sure nobody crashes - effectively switching it between being a roundabout and being a through road - but it's still pretty weird.
The problem with Colchester is that it's plagued with heavy traffic and bad drivers.
It's much more dramatic near Dover: traffic is channelled from the port straight into a bunch of roundabouts. My dad was metaphorically scarred for life after disembarking a ferry with his Italian campervan in 1986.
I moved from the UK to the US in 2001. I then learned to drive in the US (Had no need to in the UK).
Sometimes I dream of the UK, my dreaming brain realizes I'm on the "wrong" side of the road. So it tries to switch me over, but that means traveling to the US, so I then have to get on a plane to... drive on the right side of the road. I do it less now that I'm aware of what's going on, but it was very disconcerting to wake up from!
Actually driving in the UK (while awake!) is much easier, as you're just kind of following the flow of traffic.
In particular I've found that driving on the continent in a UK car is a lot harder than driving on the continent in a local hire car, beyond the lower visibility you get when merging etc.