I am just gonna link this article:
Caring For Your Introvert.
One of the things the article points out, is that while introverts can understand extroverts, the reverse isn't usually true. Extroverts have a really hard time understanding introverts. And since we live in an extrovert world, we end up with a minority maligned sub group, who becomes disenchanted from society.
Introverts are probably THE most misunderstood, and discriminated-against sub-group out there.
Edit: I am also an introvert, preferring quiet times alone mostly, or occasional conversation over IMs, e-mail, texts, etc. Places where I can respond or not, or at least take my time in crafting a reply. Being around too many people, or talking to a group of people, really is draining. I find myself wanting to go and be by myself again.