If you have some semblance of organisation of your files and use a lot of PDF and markdown files (#obsidian) or #notion, check out Khoj. It's an insanely easy app to have either a local (LLAMA) or API LLM (ChatGPT) query your materials and talk about them. Setup is mostly done in the UI. It's search is really good too. Game changer as it helps reassure me that I am not missing things in my complex file tree.