I've observed that many people, when they think about stuff, choose to limit themselves to only what they know. That is, they revisit the facts and opinions with which they are familiar, over and over again, trying to squeeze something new from them.
What I've always found, that tosses a big wrench into the works, is not what is known but rather what isn't. Some people might think it is a contradiction to think about what you don't know, since obviously you have nothing in your head that relates to it, but what you do have is essentially dangling threads. Information that only goes so deep and then suddenly stops. If you want, you can explore these.
You start by inventorying what you already understand, then gradually decompose that into more precise fragments. At some point, you either bang into an assumption or you just draw a blank. Blanks are easy since you know that you don't know, so you now have something to learn about. Assumptions however can be very hard to recognize. They often appear as concrete knowledge, except they are not based on any underlying facts that you know. What they really do is cleverly hide unknowns, removing uncertainty, but at the cost of quite possibly being wrong. Most problems start with at least one faulty assumption.
So you ask yourself, what do I know that really are facts? Are these absolute, or are they relative to some specific context. Once you've filtered out the facts, what remains needs clarification. With these you can start asking questions, and with those you can search for answers. It's a long, sometimes slow, loop but if you dig deep enough you'll find that you can uncover all sorts of unexpected things.
There are of course "right turns" that come up so unexpectedly that no amount of thinking would ever lead you to them. There is little you can do about these. You never want to go too far down any rabbit holes, since they might lead you to start reconstructing things incorrectly and end up creating worse assumptions.
One thing that helps is to analyse whether or not the people you are talking to are themselves referring to actual knowledge. I've often found that people will confidently rely on some pretty shaky assumptions and that it is inversely proportional. The shakier the assumption, the more some people convince themselves to believe it. It's considered rude to point that out, so often what you need to do is note down what they are saying and find an independent way to verify it. Two people saying the same thing is better, but it's best when you can break it down to real underlying facts that can be shown to be true. Digging in this way always brings up plenty of unexpected issues, some which turn out to be dead ends, but many which lead to valuable insight.
Things generally go wrong, not because of what we know, but because of what we missed. Learning to think deeply about what might be missing is a valuable skill. With practice, one starts to see the weaknesses right away, and you don't really have ponder them for days. Rather, in the midst of discussion, you become aware of a blind spot and start asking questions. If you confront you own assumptions, you often find that others were operating with similar ones and that they are quietly hiding something nasty. Getting that out into the open usually saves a lot of trouble in the future.