Most recently I've been interested in what's happened with the 4-color theorem since the 1976 computer-assisted proof, and decided to use GPTChat instead of google+wikipedia. GPTChat had me convinced and excited that, apparently the computer-assisted part of the proof has been getting steadily smaller and smaller over the years and decades, and we're getting close to a proof that might not need computer assistance at all. It wrote really convincingly about it! And then I went and looked for the papers it had talked about. They didn't exist, and their authors either didn't exist, or worked in completely unrelated fields.