How to interact with an introvert

http://themetapicture.com/how-to-interact-with-the-introverted/ This thing is awesome, I am a bit introverted and can't understand how some people can talk to everyone all the time and this does a good job explaining it in a visual way.

Yeah this thing explains it so well, I tend to talk to a lot of people while gaming but otherwise I keep to myself. There's only a certain number of people I even let get close to me, but even then I can still count them in one hand at this point.

I have learned to pretend to be an extrovert - hostess, receptionist, guide, etc. when a job calls for it. However, at the end of the day, I wish I owned a hot tub and the world would blow up. Why can't extroverts understand this?