I have a PDF file of every web page I've ever read/found interesting since the last century. This collection of about 70,000 files turns out to be a massive database of things I'm interested in.
I'd love to have an AI analyse this collection, and do things with it. What, exactly, I don't quite know - recommend other subjects that are similar, find aspects of the things I'm interested in that I don't know about yet, maybe even find similar sites to those found in the PDF metadata that would fill in gaps in my knowledge. Not sure yet how that will work, but I'm thinking about it regularly - usually whenever HN prompts me with Cool AI Thing of the Day™ ..