How important documentation is. Having to go back to code I wrote years ago, figure out what I was trying to do, relearn specific add-ons/libraries that were o

How important documentation is. Having to go back to code I wrote years ago, figure out what I was trying to do, relearn specific add-ons/libraries that were only used for that project, then figure out all that has changed/abandoned in the intervening time, avoiding the temptation to start by refactoring... Very difficult, and very easy to be doing unprofitable work because my state of programming mind is so much different each time than the project that is now years older.