"What you know about the people whom you know at all well is truly amazing, even though you have never formulated it"

In this quote, Harry Stack Sullivan is highlighting the unbelievable depth of understanding that we have about individuals we understand well, even if we have never knowingly thought of it. He recommends that our understanding of others exceeds what we can take into words or articulate, and is rather a deep and user-friendly understanding. This understanding is built through our interactions and experiences with these people, and it is something that we might not even recognize we possess. Sullivan's words remind us of the intricacy and richness of human relationships, and the power of really understanding somebody on a deeper level.