I don't count myself amongst the wise btw. But I am at times surprised by how age masks foolishness, and people ask me for advice which I wouldn't trust!
Richard Rhodes discusses the scientists at Los Alamos, confounding the more urbane partners: Fermi insisted on leading square dances at the saturday socials, despite not having danced the square in his life: he just spent some time beforehand watching how it was done. Apparently he did it perfectly. I consider that evidence of wisdom beyond words: He watched, he learned, he didn't ask. A scientists wife called Claus Fuchs "penny in the slot" because he said nothing, unless asked. He didn't volunteer. When you consider his role in history, maybe he was well schooled? A natural spy? Again, he didn't proffer advice, but he was very good at what he did (as were the Krogers, and many others. Whereas the amateurs recruited in the US were by and large bumbling fools)
I suspect spying-wisdom, like other wisdom, is not found in self-help books.