I am a self editor, I am the editor of myself.
I have a ton of thoughts, ideas, knowledge which passes through my mind at every instant, and by editing it I mean selecting what to remember, what no write down, what to focus on.
Being the editor of the self means to listen to what our deepest feelings tell us to do about anything we come up with. It means to be selective, not to become too attached to impressions which in the end or in the long term are not too valuable.
As a movie editor must look at every single frame in a perspective which allows him to fit and consistently include it in the whole film, in the same way I need to plan and live every moment as only a part of my entire life, or better, as a very valuable subsection of my time on planet Earth.