Part of showing gratitude for knowledge is that when you are in a gathering, and an issue comes under discussion that you do not know about, and you learn it from that gathering; then, when you are in another gathering and the very same issue comes under discussion again, you say: "To tell the truth, I did not know about this issue, but I heard it from so-and-so in such-and-such a gathering, so I came to know it." When you do this, it is as if you have fulfilled the gratitude for knowledge.