Shrinking Violets

I have a lot of the purple variety around the yard but only one clump of these lovely white violets.  The phrase “shrinking violet” stems from the nature of actual violets, which are small, delicate flowers often hidden beneath larger plants in woodlands and fields. The use of "shrinking violet" as an adjective to describe someone as being shy dates back to the 16th century when William Shakespeare used it in his play Hamlet.  So many idioms we use today date back to Shakespeare.  Here's a few more: 
"For goodness’ sake" - Henry VIII
"Neither here nor there" – Othello
“One fell swoop” - Macbeth
 ”The be-all and the end-all” - Macbeth
"Mum's the word" - Henry VI, Part II
“All that glisters is not gold” – The Merchant of Venice
"Eaten out of house and home" - Henry IV, Part II
"Knock knock! Who's there?" - Macbeth  
There are dozens more.  Amazing when you think about it.