just about everything that happens to you will be interesting to your future self/your descendants/archaeologists. immortalise your to do lists, shopping lists, packing lists, things that loved ones say, things that strangers say, the phrases you hear that would make a good band name. brainstorm what to do on the weekend, list your cravings, the songs stuck in your head, transcribe birdsong, etc. i track my periods & my finances in my journal. sometimes if i really want to take a photo of something i'll restrain myself and draw it in my journal instead. sometimes i take notes for uni in there, or draft sewing patterns, or sketch when im bored. journals are self-portraits!!!!!!!