The principle for Day #22 on the 101-day book report says: "Be conscious of your thoughts and internal dialog."
I think the ego is like this little weather station in your head. All day it gathers a bunch of metrics and runs them through some arbitrary algorithm. Then it spits out some kind of one-dimensional result, like "I am miserable."
The trouble is, an identical set of circumstances on a different day can result in a totally differerent verdict. A cloud passing over the sun can turn your day on its ear.
This brings me to a bit of wisdom a friend shared with me once, "You can never attain happiness; you can only claim it."
And that's the Heisenberg trouble with your inner dialog. Like a spouse who wants to know what you're thinking, just doing inventory turns it into the wrong answer.