Best trust the happy moments. What they gave
Makes man less fearful of a certain grave,
And gives his work compassion and new eyes.
The days that make us happy make us wise.
I set up a trigger to remind myself, and the next time I noticed myself spiralling into repetitive negativity, I stepped back. Sure enough, my mind continued along its negative course. I let it. Like a balloon full of air sputtering through the air, I didn't give the thoughts any more of my attention. The feelings persisted, pushing their hoary head into my thoughts for awhile, but each time, I simply ignored the feelings.
It worked. For me, the effectiveness of the experiment was the proof.