I'm surprised how many things I expect will continue to frustrate me eventually become ordinary, not worth noticing. I wonder if I am changing, drifting into a different set of behaviors. I have to push myself to notice.
Mind Hacks: Why Your Brain Loves to Tune Out, 2012-May-18, by Tom Stafford
Our brains are remarkably good at cancelling out all sorts of constants in our everyday lives. The brain is interested in changes that it needs to react or respond to, and so brain cells are charged with looking for any of these differences, no matter how minute. This makes it a waste of time registering things that are not changing, like the sensation of clothes or a chair against your body, so the brain uses adaptation to tune this background out, allowing you to focus on what is new.