I download videos that show how to do things that I think I will do again sometime in the future. How to take apart appliances, how to tie paracord knots to hold an Apple AirTag (did this in 2016 I can see from the video).
There are a lot of good videos describing fly tying. I tie up 5 of a new pattern using a video on YouTube. After 4 years, I lose the last one in a tree. So then I ask myself a lot of questions I sometimes remember, but often do not: What was it called? What are the materials used? How is it tied? Having a collection of videos makes this easy to answer.