I have seen it happen many times, and I myself have even been on the receiving end. A possible reason is that when a person is confused and you tell them, hey, X has said something good about just this kind of problem is kinda redundant and useless. If you have internalized learned wisdom well, you probably would be very well able to speak it out directly (because you had actually applied it and seen it work, (or if something not experimentable, you’d have followed a thought experiment and reached the same conclusion independently)).

This is useful to know when you’re helping other people solve their problems, because I have this instinct to point people to original source where I read/heard the concept, and it is useful in some cases, but in most cases it isn’t. Or I should say, pointing to original source is useful at the end of conversation or after the idea has made sense to the other person not before it.