The generally underperceived extent to which we tend to imagine how the world works and then proceed to selectively recall or emphasize experiences that fit our expectations is a theme with the executioner. Getting older apparently doesn't necessarily make us wiser about this debilitating little quirk of the human psyche. By now, my two or three faithful readers are groaning "shut up or tell me something new". Sorry. The executioner wishes to be reminded of his own weaknesses often and so, if only for his own sake, pulls this foible back onto the docket because a bit of fresh evidence turned up. Those elderly who expect that growing older is an unrelenting fading of strength and energy are exactly the ones who tacitly choose to avoid the exercise that would forestall this life sentence of senescence.
The fact that it is a common, perhaps universal inclination leads one to suspect it is inherent in the operation of the mind. And I will go a bit farther and suggest that it is like, for instance, the tendency to diabetes and heart disease, a manifestation of a trait that was not harmful, or even useful at some point in our evolution but which now serves us poorly because we live in a much more complex world than the one that shaped our instincts.
Why my appetite for nagging reminders that I am readily able to fool myself? Because the blessing of our species' particular form of sentience is that choice is available to the awake, a crack in the unscalable wall of biological destiny through which we can wriggle rather than numbly climbing until we slip from being. Exercise your awareness, your skepticism and of course, your cardiovascular system. Be alive!
I just accept this as an observation:
As individuals, we tend to make what we already believe more believable by suppressing awareness of some information.
I wish I understood how individuals somehow collude to arrive at shared delusions about what has happened in the world. You will all have your favorite examples of this phenomena. The one I happen to have a handy link for is this old news story which illustrates that our benighted American voters can block out whole books full of damning facts.
[what books? this is just one of them]