Yes. If you could predict e.g. the closing price of the Dow in 2 weeks, that would be a risky prediction.
Take your Woodstock prediction as an example, which I think can help to clarify:
Did you write it down at the time? Tell someone? My first question is whether, when Woodstock wend bad, you were reminded of one a number of feelings about the show you had before it, and forgot a whole host of other feelings not confirmed in retrospect. This is a failure of human cognition that everyone makes, so it’s important to be self-skeptical. That’s why public predictions are more reliable: there’s no thread of false memory, and if you make a million public predictions people won’t be so impressed when one of them turns our right.
Next, how unlikely was it, on the information you had by normal means on the day before a show started, that you would be able to guess that the show would turn out as it did? I think “this show will turn out bad” is sufficiently concrete; the fact that the Wikipedia article on it has a “controversy” section is to my mind a ‘hit’. But by that standard, there are only really two outcomes: good and bad. You guessed bad. How often do music festivals “go bad”? Woodstock '99 isn’t the only one, I can name another one that went bad this year (Fyre). It does not seem all that uncommon, maybe not 50-50, but not a million to one either. And how much information about the concert did you have at that point? I wasn’t there, but from the Wiki page it seems like the way things were set up, e.g. banning outside food and price gouging on the food for sale, increasing corporatization, and the style of music, might suggest that there would be a lot of angry people at the concert. Did you have enough information on that Thursday that a reasonable person might have guessed that things would go south?
All told, it seems like your prediction wasn’t public, it was concrete, but it wasn’t particularly risky. That’s how I would score it.