As you can certainly guess, I've long loved that episode from Boswell's diaries. (Please start here if you missed it.) It's got all the ingredients: extravagant self-praise, adolescent classical allusion, and burning upon urination.
The comic pacing is almost too perfect to be nonfiction. Intrigue, fluttering heart, overweening braggadocio, completely insufferability-- and then, at the periphery of his senses, a faint itching and burning...
I love how he saved face by bullying the poor pseudonymous Louisa (Anna Lewis). As Dr. D.W. Purdie describes*, she "could honestly assure him that she was free of all signs of infection yet conceal, unknown to herself, gonococci... Boswell was unlucky." I wouldn't go that far. The guy screwed prostitutes all over London and, eventually, the continent. He usually didn't use the sheepgut "armour" of the time. And he died ridden with probably about 55,273 different sexually transmitted infections.
It would have been great to drink with Boswell. I really like the guy. It's probably not an accident that one of my favorite novels is Pale Fire; that book begins with an epigraph from Boswell's Life:
"This reminds me of the ludicrous account which he gave Mr. Langton, of the despicable state of a young Gentleman of good family. ‘Sir, when I heard of him last, he was running about town shooting cats.’ And then in a sort of kindly reverie, he bethought himself of his own favorite cat, and said, ‘But Hodge shan’t be shot; no, no, Hodge shall not be shot.’"
I never really understood why Nabokov chose that particular epigraph. Boswell, sure; our honest narrator Kinbote is similar to Boswell in some of the obvious ways, but dissimilar in that I wouldn't want to drink with the guy. As much. Although I do like the line, "I laconically suggested that he 'try the pork.'"
*A pretty fascinating article, as far as articles in medical journals go.