Dirac invented quantum mechanics as we know it. He unified everything, adding much along the way into the modern formalism. His book from The Principles of Quantum Mechanics feels completely modern,although it was first published in 1930. However, he was also very humble, giving a lot of credit to others for things he himself discovered.

Kurt Gottfried posted a paper in arXiv:1006.4610 where he carefully examines the history of quantum mechanics by going to the original papers and getting the record straight. This highlights the central role Dirac played through out this. This cute paper is nice, with tons of references, some fun anecdotes, and just enough equations to get the details right. I highly recommend it.

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Time flies like an arrow. Fruit flies like a banana.
-Groucho Marx

Is this the interaction picture?

W. Heisenberg and P.A.M. Dirac, two of the founders quantum mechanics, were on a steamer boat from America to Japan. Heisenberg, a social butterfly, would participate of all the social activities, while Dirac, always very shy, would just sit quietly and watch.

“Heisenberg, why do you dance?” Dirac honestly inquires. “Well, when there are nice girls it is a pleasure to dance.” Heisenberg responds. Dirac turns silent for a few minutes, involved in deep thought. He finally questions, “Heisenberg, how do you know beforehand that the girls are nice?”

According to Heisenberg, this is a true story.

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Lord, grant me chastity and continence… but not yet.
-St. Augustine

Most probably you have seen that famous Solvay Conference Picture, the one with Einstein, Dirac, M. Curie, Schrodinger, Heisenberg, and many other famous physicists.

The famous Solvay Conference picture.

We decided to take a group picture in the courtyard of our building in Harvard imitating that picture.

Group Picture Imitating the Solvay Conference

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“If I understand Dirac correctly, his meaning is this: there is no God, and Dirac is his Prophet.”
-Wolfgang Pauli