Why Shakespeare is Shakespeare: Shiny!

Every writer I know is a magpie at heart.  Magpies find shiny things everywhere.  They pick up phrases, new words, memes and T-shirt slogans.  They know how medieval beer is brewed.  They can tell you forty-five reallyinteresting things about rats.  They pickup names, and interesting geographical facts, and local info from placesthey've been.  And sometimes they usethem just because they're there, or because they like to boast, just a little,that they know more about rats, or Martini-mixing, or recreational bomb-makingthan you do.
In the inexperienced writer, this is called data dumping, or"I've suffered for my art, now it's your turn." They spent a whole afternoon finding out how a corset-maker made corsets, and now they'regoing to tell you.  Everything.   
In the good writer, or the great writer, most of the magpies' shiny things end up in the closet marked "Spare Art Parts," but occasionallythe writer will give you something just because he has it and it's shiny and itworks in the scene.
An example.  Iresearched a book called Chasing Shakespearesduring the Millennium Year in London. I was writing from the point of view of Joe Roper, who had never been toLondon before.  Joe was coming into Londonfrom Heathrow via the Tube—Joe was poor, the Tube is the cheapest way in--so I came in by Tube too.  This was Joe's first sight of London and I took notes.  I took pictures of the upholstery; I wrotedown the ads he saw.  Some of them were funny—eatyourhandbagbitch.com, sminting, a bizarre ad for Asahi Beer—and they fed into a moment that wouldappear much later in the book, when Joe sees a phone advertisement quotingShakespeare and realizes that for the rest of his life, even if he chooses to ignore Shakespeare, he'llbe haunted by Shakespeare's words. 
Shakespeare is full of shinies.
Shinies are little goodies that are not necessary to theplot.  They may add a little, but notmuch; some other detail could do as well. 
And that's the trouble. It's not that Shakespeare has to be educated; we know he was, though he may have got it mostly because he hunted it down.  It's not that he had to be educated as a lawyer to know how a lawyer speaks and thinks.  It's certainly not that he had to come from a particular social class.  
It's the shinies.