@WhatMattersMost
Th markings are very clear, and I'm concerned about your safety and other drivers' if you struggled to do the right thing.
Somewhat harsh I think. Everybody makes mistakes, no matter how long you've been driving or how good you are normally. The worst thing you can do is make someone who's anxious about a situation on the road more anxious.
Then again, I feel from the tone of your post you get a little self satisfaction from the put down.
For what it's worth OP if you happen to read this, I remember being told, probably during my car, but potentially my HGV, that the standard at 4 exit roundabouts is lane 1 for 1st and 2nd exit, lane 2 for 3rd and 4th exist. That's just a general "rule" though.
The most important thing is to read the signage on the approach to any junction. I'd imagine like most people you have a sat nav of some kind on and are possibly focusing on that to direct you.
If you do find yourself in the wrong lane, its far better to come off at thr wrong exit and then come back on yourself than to cut across lanes to get to where you want to be. Also, don't feel too intimidated by someone beeping. More often than not it's a warning to you that they are there, or that you are moving too close to them or potentially doing something dangerous, rather than them being overtly aggressive.
Everyone gets it wrong from time to time, from newly passed drivers, to Advanced Driving instructors.