Scenario
There you are, you finally found some time to pick up your analysis where you left it months ago. You just got up to make a coffee, ran into a colleague, opened your email inbox, got a message from your professor and all of a sudden a quarter of a year (or more) has passed. Never mind, here you are and you are going to dive into this work again.
You are determined to continue, but you are struggling to remember where you left off and why you put this line of text here. There really should be some guidance and it should explain where you are and where to go from here!
If future you is so confused by what you left them, imagine how lost other people might be.
Solution
Document your project and the steps you took and ideally also the steps you intend to take. Documentation can come in a lot of forms: a README file in the top folder, an inline comment in your script, a yellow comment box in your word document or a note in wherever you put your notes, virtually or physically. If your note works for future you, great, if it works for other people as well awesome!
Start documenting you work now, e.g. by following the DCH Readme File Guidelines. 2023. https://doi.org/10.5281/zenodo.7447616.