When I was younger and wiser, I loved the conversational tangent. It burst out in those irrepressibly flowing, intense, interrupting dialogues. We were at a café or pub, lingering in the half-light, a second cup, or a third round, moving from the gossip and quiddities of our days to larger, more abstract issues. We discussed memory, the meaning of life, where we might be going, and why.

The tangent was not a dining-out tale, something humorous and easily retrievable from my past with which to regale an audience who was giving me a meal. Instead it was a method to unknot something: we were putting our world to rights and figuring out how to live.

It didn’t always go well. I remember an evening in Ketcham, Idaho. We were twenty-two, full of life, two-thirds of a summer’s drive across the country. We spent a long dinner discussing the future. Evidently we were callow, obnoxiously opinionated, assuredly solipsistic, or possibly just loud. A guy came up to us on his way out, white beard, old (probably in his fifties). He stopped and said, in a fly-fisherman voice, “You guys are completely full of s—. Just stupid. You don’t know what the f— you are talking about.” He was probably right.

When we got into one of these tangents, a go-to was my Graham Greene tale. I never read much Greene when I was young. His paperbacks were in the corner, with their white covers and garish