Once apon a time we got a piece of paper with every roll of film that told us how to expose the film without a meter. They never called it the sunny 16 rule (sweet 16 as you called it) but that is what it was. Anyway I took a photo of the moon recently which came out grossly everexposed. I remembered the piece of paper and used the rule. It worked, got me within half a stop of correct first go.
with all the doo-hickeys our cameras provide it easy to forget the old-school methods that have worked since the caveman days