I consider myself an introvert. I can hold a conversation, tell silly jokes and make people laugh but I prefer to be alone. I feel tired and drained when I mixed around with people, when I'm in the mall or congested public places.
When I was younger, I thought I was abnormal. Then I found out that those extrovert people are the culprits - they dont have enough energy, so they feed on you - like a vampire.
I understand there's some techniques to make you vampire proof but for the time being I only socialise with non-vampires.
Here's an a article on energy vampire:
Intuition, Medical Intuition and Intuitive Healing