In our world, we spend a lot of time talking about what we're doing-–producing, trying, discussing, making, building, iterating, what-have-you.
Unfortunately, I don't think we spend enough time talking about what we're “quitting”. And when we do, it's often comes out like, “I really should quit …”, and then we go on to fill in the blank with some vice or habit that we know isn't good for us, but that we're really unlikely to quit any time soon. (My BS sensors go off any time I hear the word “should”. It's often a sure give-away we likely haven't really reconciled what ever comes after the “should” with our core values.)
Even more devious then the vices--sometimes--are the multitude of really GOOD things that are distracting us from the GREAT things.
Or, get backed into a place where we can only do a whole bunch of great things at an “okay” level of performance, rather than a smaller number of things with results we're really proud of.
So, I submit for your brain diet an episode from one of my favorite podcasts, Freakonomics (the wonderful spin-off radio series by the authors of the best-selling book). The Upside of Quitting: A Freakonomics Radio Broadcast.