A famous great anecdote about Dirac (and Bohr and Rutherford) was in Absolute Zero Gravity:
Young Dirac arrived at Niels Bohr’s institute with a glowing recommendation from the great experimentalist Ernest Rutherford. A few months later, Bohr remarked to Rutherford that this marvellous Dirac hardly seemed so special: he said nothing and he did nothing. Legend has it that Rutherford replied with the following story:
A man went to a pet shop to buy a parrot. There was a grey parrot that knew a few words selling for one hundred dollars. There was a blue parrot that could sing and tell stories for two hundred dollars. There was a beautiful green and purple bird that spoke several ancient languages for five hundred dollars. And there was a nondescript brown bird priced at a thousand dollars.
“A thousand dollars!” exclaimed the would-be buyer. “That must be some bird - how many languages does he speak?” “Just English,” admitted the shopkeeper.
“His vocabulary is extraordinary, perhaps?” The shopkeeper shrugged. “Not really”.
“Does he sing, then?” “No,” said the shopkeeper. “Most days this parrot doesn’t even talk”.
“Well, does he do acrobatic tricks or something? What on earth is so valuable about that parrot?”
“Sir, this parrot thinks”.
Rutherford concluded, “Dirac thinks”.