Why is it that every git tutorial always suggest to use git config --global to set the git configurations. And usually without telling the user that the --global part does.
This is actually bad advice. It will change the behaviour of all clones which is rarely what you want — at least in the long run.
In the long run you want fine tuned setups specific for every clone and global setting which you might have forgotten about in a month time are a hinderance.
So please stop using --global in your tutorials.