I absolutely love this from the brilliant Brendan Dawes:
After a recording session on one of those large mixing desks, after you’ve twiddled countless knobs and push around many faders you do something called zeroing the desk. This is were you turn every control and push every fader back to zero, so that when the next engineer comes in he or she isn’t going to jump out of their seat when a large sub-bass whacks them straight in the face and possibly blows something up. It’s a polite thing to do for your fellow sound engineer.
Brendan talks about applying this same principle to digital work. Brilliant.
As a musician and former sound engineer (I worked at a venue/recording studio in Pittsburgh), zeroing out a board is one of the cleanup things you do once the session is complete or the concert is done. You have a mixing board like this: