Parent was writing about a university LECTURE which is different from a TEXTBOOK (which is different from primary sources), so yeah, consulting other sources is checking the facts.
Oh I see what you're saying. It was slightly ambiguous.
But in any case, I didn't read a single textbook at uni; it was all lecture notes provided by the lecturers (fill-in-the-gaps actually which worked waaaay better than you'd think). So the answer is still no - I didn't fact check them and I didn't need to because they didn't wildly hallucinate like AI does.
You should have a mental model about how the world works and the fundamental rules of the context where you're operating. Even though you might not know something, you eventually develop an intuition of what makes sense and what doesn't. And yes, that applies even to "university lectures" since a lot of professors make mistakes/are wrong plenty of times.
Taking an LLM's output at face value would be dumb, yes. But it would be equally dumb to take only what's written on a book at face value, or a YouTube video, or anyone you listen to. You have to dig in, you have to do the homework.
LLMs make it much easier for you to do this homework. Sure, they still make mistakes, but they get you 90% of the way in minutes(!) and almost for free.
I don't think it's (necessarily) equally dumb. Maybe if comparing LLM output to a book chosen at random. But I would feel much safer taking a passage from Knuth at face value than a comparable LLM passage on algorithms.
I was being facetious but am now extremely curious about large portion of the knowledge obtained by subject matter experts in any given field has never been published - this is not only strange to me in the small but you are claiming that this is large portion so I am wondering if you have any example(s) to share?
LLMs are vastly superior to compile and spread knowledge than any other thing preceding them.