We all know it: days after "someone" did changes on a system, somebody finds out that anything doesn't work properly. And then we have to figure out who has made those changes. "was it me? was it my colleague? was it one of the developers?" and so on... Keeping track of all the changes in the configurations-files would be very nice. We could see the differences of the configurations and we could just rollback to an old state. Beside this we also have more opportunities to find out who has made those changes. VersionControlSystems is what we need in those cases and etckeeper is a very nice wrapper for well known versioncontrolsystems.
There is a nice git-game on github: https://github.com/hgarc014/git-game