This is what some call "mindfulness". The ability to be aware of feeling an emotion, and then to be able to step outside of that and ask "why am I feeling that?". You can then start to work on the cause rather than the symptoms.

If you ever get taught meditation, a lot of it is about letting the mind go in the direction it wants to go, catching it, noting it, and then resetting. Lather, rinse, repeat.

You just did it when you were writing an essay.