The worn out, spent, or run-down sensation experienced after being around a lot of people. Some people even experience headaches and body aches similar to those associated with an alcohol based hangover, even when they did not consume any alcohol to cause one. Common to introverted people.

When you eat dirt for the first time and leave your family to build a shack in the woods

When you wake up clear in the head and feeling great otherwise, this is the sick feeling you get in the morning that you may have made a complete ass of yourself at the party the night before or offended several people you had never met before.