Im mostly disturbed by the "most powerful" part because this is subjective to project and how you work. It's not a very common case for me to commit parts of changes in a file because in most of my cases all changes I do to a file belong to the same commit since I work with feature branches. However when I do need this it's indeed powerful but judging by the enthusiasm of the post and title it just smells like the endorphin release of new feature discovering.