Aleph

I immediately thought of this:

"I never mentioned a man but with the view
"Of selling my own works.
"The tip’s a good one, as for literature
"It gives no man a sinecure.

"And no one knows, at sight, a masterpiece.
"And give up verse, my boy,
"There’s nothing in it."

"Hugh Selwyn Mauberley", Ezra Pound
 

Or, as Andre Gide said:

"If a young writer can refrain from writing, he shouldn't hesitate to do so."