Predictions are hard. Especially those about the future. And especially those about humans.
You'd think it work something along these lines:
You make a prediction. It turns out to be right.
You make a prediction. It turns out to be wrong.
Clean, precise and simple. It's either true or false. Or true to a sufficient amount of digits to justify the wanton use of the phrase "Pearson product-moment correlation coefficient".
You'd think it be that easy. But then these things happen:
You make a prediction. Because you made this prediction, people made a conscious effort to make this prediction come true, and thus made it happen.
You make a prediction. Because you made this prediction, people pulled together and made it their solemn duty to make this prediction not come true. And this it didn't.
Suddenly, the prediction becomes a part of the thing it's supposed to predict. Which, to be sure, makes the whole prediction business that much trickier. Not as clean and simple as one would think.
You'd think this would be the end of it. But no! It gets worse!
You make a prediction, and people act in such a way to facilitate the prediction coming to pass. However, their actions are of such a nature that they undermine the conditions which would make it possible to come true, and thus it doesn't.
You make a prediction, and people act in such a way as to try to prevent it from happening. However, in their eagerness they manage to do precisely those things that makes the predicted thing happen, and thus it happens.
As you can see, predictions can have all kinds of effects on things. Especially humans. Things can happen because you predict them. Things can fail to happen because you predict them. Things that might have happened might unhappen because of your prediction. Things can be caused to happen by your prediction of them.
I predict you managed to get your head around all of that. And that you're thinking: well, it can't get any worse than that, can it?
Well, you could predict something that is quite obviously going to happen whether anyone predicts them or not. And that others have predicted before, but not in quite as loudmouthed a way. By being among the most vocal of those doing the predicting, you elevate yourself to a higher social status by virtue of saying true things about the future. Loudly.
To which I predict you thinking: wait, predictions can change the thing they predict, the person doing the predicting, and the relationship between predicted, predictor and predicated? What maze of recursive mutually dependent dialectic twists and turn is this?
You'd be excused for thinking that sometimes, it's easier to not think about these things.
Such as in the comparatively easy hard sciences. -