We do get questions like that a lot. However, almost all of them get closed.
If you think about it, this is asking the users of this site to do research for you that is honestly much better done yourself, since its your memory. Only you know if what is found is correct, and there's even a possibility that you misremembered it beyond all recognition, or dreamt it up, or the person you heard it from did so. Doing the research might tickle your memory a bit to help keep you on the right track, whereas we have no such guides, and indeed no way of knowing if this is even a real thing.
Another large part of the issue is it seems that people who ask questions like this tend to be the same kinds of people who are unable or unwilling to help us out by listing what research they tried and failed; either because they haven't tried any, or because doing research and editing the question to respond to comments would be work and their whole point of asking us was to avoid the work. (I'm not saying you are like this, but that's our experience with others). Either way, this site expects that information in a good question.
So what would a successful such question look like? This is speculation on my part (unless someone can dig up an example of a good one from our site?) but I believe it would have a total information dump of everything the asker can remember about the quote. Where and when it was heard, what context it was used in, what it was explained to them to mean, etc. A lot of that stuff I see above.
It would also list everything the asker already tried to do to track it down themselves, including links, and clues found, and what information was not found there. There would be a decent amount of this (3-ish would be great, but there should be something). This is what I'm not seeing there right now.
