Henry David Thoreau, "Walden."
ADDED: This passage cries out for a link to "Caring for Your Introvert":
Extroverts have little or no grasp of introversion. They assume that company, especially their own, is always welcome. They cannot imagine why someone would need to be alone; indeed, they often take umbrage at the suggestion. As often as I have tried to explain the matter to extroverts, I have never sensed that any of them really understood. They listen for a moment and then go back to barking and yipping....
We can only dream that someday, when our condition is more widely understood, when perhaps an Introverts' Rights movement has blossomed and borne fruit, it will not be impolite to say "I'm an introvert. You are a wonderful person and I like you. But now please shush."
How can I let the introvert in my life know that I support him and respect his choice? First, recognize that it's not a choice. It's not a lifestyle. It's an orientation.