Michelangelo Buonarroti,

Michelangelo had heard about a big block of marble eighteen feet high that was sitting around in a yard. He went to the town hall to ask about it and was told that the mayor had promised it to a sculptor called Sansovino. Another official said he had heard it was meant for Leonardo da Vinci. In any case, the best thing would be for Michelangelo to forget about it because it was worthless.
“Didn’t they tell you?” said the official. “A fellow called Simone da Fiesole started to carve a statue years ago and the fool began by drilling a big hole right through the block. If it had been a clean hole maybe something could still be done; but then the guy goes and chips half the stone away from front and back of the hole too. A dozen sculptors have gone to look at it and they all come back here either angry or nearly crying. It was a beautiful block too, without any flaws. Da Fiesole ought to be hanged.”
Michelangelo knew the story and he had often wondered just how bad the botch was and whether he couldn’t cut a figure out of that block, hole and all. That a dozen other sculptors hadn’t been able to do that didn’t mean a thing to him. “Can I at least go and see it?” he asked.
In the yard of the Office of Works Michelangelo spent a long time at the stone. He walked around it, took measurements, stood in front of it in thought.
“Now you see for yourself why everyone else rejected the darn thing,” said the old caretaker with all the keys; but he got no answer from Michelangelo.
As soon as he was home Michelangelo started drawing and making a little wax model of a David, which had been da Fiesole’s subject. When he was sure he could carve his figure out of the botched block, he asked the mayor, Soderini, to give it to him.
He carved the David, according to Condivi, though few believe this, in eighteen months and “extracted the statue so exactly that the old rough surface of the marble [and da Fiesole's chisel marks] still appear on the top of the head and on the base.”