This shifting-probabilities gimmick at 538 reminds us that probabilities aren’t the same things as predictions. We don’t know how the probability cloud will collapse into a singular reality (sorry to go all quantum physics on you). We live in a world that at both micro and macro levels is chaotic, fluid, and fundamentally — if I may use another highly technical term — squirrelly.
Unfortunately, it’s pretty much impossible to live a normal, emotionally stable life without finding various perches of certainty, belief, faith, conviction, etc. You can’t go around in a probabilistic daze.
Evolution rewards snap judgments. Sometimes you just have to take off running. But we make mental errors all the time. For example, we typically fail to see how low-probability outcomes will become far more likely, if not a certainty, given enough opportunities. We also overestimate the extent to which our direct experience predicts future probabilities. Anecdotes mislead. So do statistical studies with very small data sets. (Here in the science pod we keep on the lookout for studies that turn out to be based on the thoughts of three guys on bar stools.)