[webhat]

I go as far as to have a dedicated project notebook for big new projects, I write everything down that I come across that I need to remember or need to question.

I've often been dropped into codebases where there is only a month to question the previous maintainer before all the business knowledge is lost as they move on to bigger and better things. So getting all the questions/queries down asap is the fastest step to get the undocumented business logic documented.

Even when you can't ask the questions I like to turn all the unknown unknowns into known unknowns. :)