Buying a Udemy course was a purchase that made me feel old. Not aged, but like I'd made one of those Old People on The Internet mistakes. I bought it through Stack Social, which is a pretty sketchyy site I'd never heard of, but I had heard of Stack Exchange, a much better and more trustworthy site, and I just made an Old People mistake.
I only learned I'd be taking it through a third party when I went to redeem my purchase. In firm words under the course links, Stack Social reminded me "no refunds," because that was a question I was thinking about at that point.