I really enjoyed your trip report, thanks for posting it.

"My head was now swimming, and they turned off the lights in the cabin. Is this normal in premium cabins, even for a day flight?

Yes, it is very normal and can be seen as a sign of amateurs onboard when they leave the window shades wide open the whole flight. You have a lay flat seat, quiet environment, pillows, blankets etc, it is designed for sleeping and bright sunshine really impacts the ability to sleep.

Thanks again for posting, an enjoyable read.