If it makes you feel any better, the diagnosis doesn't really help this. It's just less 'you don't even know for sure you're x' and more 'stop blaming your x for everything'.

YEAH

Neurodivergence can manifest partly in the form of sensory sensitivity, which can include light sensitivity.

I'm not sure, my partner is autistic. She doesn't like bright lights, but she hates changes in brightness even more, so the lights being on helps to deal with the flickering from screens.

It's not dark rooms necessarily, but low stimulation environments. Many ND conditions limit mental "bandwidth". Sensory processing can eat up a lot of that bandwidth normally. Throw in something like socialising, that eats even more, and we can saturate.

The manifestation of that saturation can vary a lot. My personal preference is a quiet, well lit place, with a static environment. It's change and ambiguity that cause me problems. I fully understand the appeal of darkness, however, particularly if your sensory filtering on intensity is prone to failing.

I just like the mysterious hacker or vampire vibe.

My girlfriend has a hobby of growing/propagating/selling desert plants. The grow lights fill her living room, and they are intense. 😭

Thankfully, she knows me, and she turns them off whenever I come over.

I like the amber light some of those give off (LED Edison-style bulbs with a dimmer). My trick is to hide them behind objects (like a row of books) and put them on a smart switch so I don’t have to get near them — they light up the wall/ceiling behind the object with a nice warm glow and I don’t have to look at them directly.

I can't emphasise enough how much I'd like people to warn me about noise in advance

My wife and I even do a countdown from 3!