I just cloned a git repository and checked out a branch. I worked on it, and then decided to remove all my local changes, as I wanted the original copy.
In short, I
For discard all i like to stash and drop that stash, it's the fastest way to discard all, especially if you work between multiple repos.
This will stash all changes in {0} key and instantly drop it from {0}
{0}
git stash && git stash drop