Our future selves often have different enough mental context and frame of mind to almost be a different person.
A common temptation when we are writing notes is to use mental shortcuts and implicitly refer to the current ideas in your mind or the current context you have available which makes it harder for your future self to get value from the notes.
To make them valuable you have to take care and provide enough information to help your later self cross the inferential distance and re-discover the insight you had.
Other benefits include the following
This makes producing actual publications ready for wide consumption far easier as you already have a lot of material coherently presented.