"Fred should really cut back on drinking; he just started seeing someone too; like that's going to last... wait, I don't actually have any reason to think that it wouldn't..."
Do you need an articulated reason? If your subconscious ran the numbers and reported the result without showing you its reasoning, that doesn't mean you should ignore it entirely. Perhaps when you notice predictions like that, you should write them down and see how they do?
Or could it have been an subconscious emotional response like bitterness or jealousy? Those get in the way of clear and rational thinking a lot. I could be totally off on this, of course, since you did say it was a bad example.
Recently I've noticed that, while introspecting, my internal monologue will state an opinion on a preceding thought, and I will feel an immediate repulsion towards that phrase as something disingenuous or alien. I will then recognize it as what I've come to term a "cached phrase". A variation/subset of cached thought, it is usually a string of words or that one might hear in a movie or something a friend or coworker would say, but comes to mind when you yourself are thinking about a domain associated with the conversation from the movie or friend.
Some (half fabricated) examples:
I wonder if it correlates positively to the OCD spectrum. I notice it quite frequently in myself (I'm not diagnosed OCD but suspect a slightly higher than average presence), and sometimes struggle to determine whether it's an opinion I truly hold, or if my hypothesis is an actual explanation for its appearance, or to what degree one of the two is true. Do I really feel what I think? It is too often ambiguous to myself.
Perhaps it is related to the concept of mentally modeling other people. We have our models of what other people would say in certain situations, but in this case, a random model's opinion is invoked involuntarily.
Does anyone else experience this? Do you agree with my hypothesis, or are these actually genuine thoughts; subconcious-level emotional reactions? Is there, or can we develop, a heuristic for determining where a certain thought or opinion lies on the spectrum between the two?