The Incognito Lounge by Denis Johnson   Living with a poem—in a long-term relationship, I mean, that’s mostly internal and entirely one-sided—is a bit like periodically digging in a familiar spot, each time recovering a trove of shards of one’s own memories.  The poem hasn’t changed, but the reader tracks his or her own progress (or, I suppose, decline) in relation to the act of the mind on the page.  That’s how it has been between me and Denis Johnson’s “The Incognito Lounge,” the title poem of his collection originally published in 1981, reissued in the Carnegie Mellon Classic Contemporary Series five years ago.  It’s a volume that a lot of writers my age (and a bit younger, and a bit older) can quote…