My friend Bob was feeling down recently.

At first he thought it was just the Orioles. Then he said it was bad dreams about Mr. Boh’s stick body. The potato chip girl turned out to be a dominatrix.

I thought maybe he needed some good, old-fashioned Baltimore shock therapy.

“Try eating a whole box of Berger Cookies.”

“I did—nothing—” he said. “Then I went to Gino’s, ‘cause—well, you know... Still nothing.”

Bob tried everything, even watching the GOP presidential debates. But nothing could cheer him up.

Finally Bob went to a therapist, who ruled out everything that wasn’t at the root of Bob’s funk: no mid-life crisis, no failed marriage, no repressed memories of a screwed-up childhood, no unredeemed gift certificates to Burke’s Restaurant.

“The therapist thinks she may have discovered my problem,” Bob told me after a few weeks. “It’s because I haven’t written a book.”

“That’s impossible,” I said. “You must have written a book. Everybody else has. Maybe you wrote one and forgot about it.”

“No,” he said sadly. “I haven’t even started writing a book.”

“Then what do you use Facebook and Twitter for?”

“I know, I know,” he said. “My therapist wants me to write a book—immediately. I just don’t know what to write about.”

“That’s never stopped anybody,” I told him. “People write books about anything that crosses their minds. Some people even write books about the same thing over and over.”

“They let you do that?” Bob was dumbfounded.

“Pick an idea, write 300 pages about it—presto: a book.”

The look in Bob’s eyes was like a deleted scene from a John Waters movie.

“Yeah, yeah!” he said. “How about a book about giant eel that slithers up out of the Chesapeake and eats Erdman Avenue from the city line to Harford Road?”

I couldn’t help it. I had to tell him.

“Sorry, Bob—been done a hundred times.”