Git from the Inside Out (2015)
> Notice how just `git add`ing a file saves its content to the objects directory. Its content will still be safe inside Git if the user deletes data/letter.txt from the working copy.<p>Holy crap, how do I not know this in 14+ years of working with git?!<p>The `git add --help` manpage seems to make no reference to this feature, it just talks about adding the file to the index.