Writing down ideas is always a very useful exercise. Having introspection is a good trait, so writing a "User's Manual" for yourself is a very good thing. Now,

Writing down ideas is always a very useful exercise. Having introspection is a good trait, so writing a "User's Manual" for yourself is a very good thing. Now, having these User Manuals in a company, I don't know if they are any useful; you may get the one tidbit of information that somebody you don't interact much with says they prefer email to chat or something. I propose an exercise: if you have people's "README's", go through them, if possible without seeing their names and test if you could match what they say they are/like/etc to who they are and what they actually are like. I simply find no correlation; everybody says they value honesty etc (including myself) and you still have no idea of how to interact with that person, or what they really value. We are really bad at judging ourselves.