Why your browser keeps saying "Enable JavaScript" even though it's already turned on

https://padlet.com/seosupremecommanderqiaiq/bookmarks-swpz4j5oowwnehoq/wish/mDRxWBqqoxDnZjb1

Look, I've seen this one a thousand times: you open a page, it flashes a banner or blocks you with a modal that says "Please enable JavaScript," and you swear it's already enabled. You're not crazy