Something that sounds made up to me but I know is not is that so many people seem to require a pitch black environment to sleep.

I don’t prefer it being super bright, but if it is so be it. I can still sleep just fine. I had a friend that argued with me that it was “impossible” that I could sleep in bright light. Yet I’ve done it quite often in my life, and in fact I used to sleep with the lights on all the time (was too lazy and/or too cold when living in an unheated place to get up and turn them off).