It can happen, and has happened to me several times, as an adult. But, I agree that it probably shouldn't be frequent. Sometimes genuine facts are presented that should immediately change a perspective.
What I am talking about is the process that starts once you encounter a new piece of information that challenges your world view: the process of evaluating if it is of quality (ie. trustworthy), or just appears so superficially. That process is not instant, and if you treat it as an instantaneous process, you're probably going to accept a lot of superficially trustworthy information (including scams, mis- and disinformation, and so on).
Neither am I. I'm saying that instantaneous adjustment to ones beliefs is possible, and should be a regular occurrence, while developing ones world view.
> accept a lot of superficially trustworthy information
No. Sometimes you can see things with your own eyes, or have a person that is trustworthy say or demonstrate them to you. Sometimes occurrences can prove a belief immediately true or false. A great example is a child realizing, for the first time, that an adult can be wrong about something. Or, a young adult who voted for the first time, realizing that politicians lie to get elected. Or someone taking drugs for the first time, to realize that perception is fundamentally fragile. There are many many examples. Again, it should be a regular occurrence, when young.
> confrontational
I didn't mean to. I consider "bollocks" to show, somewhat silly, disagreement/defiance. I don't consider defiance or disagreement of an opinion to be confrontational.