Audrey Hepburn, Hollywood star and UNICEF Ambassador:

"I have to be alone very often. I'd be quite happy if I spent from Saturday night until Monday morning alone in my apartment. That's how I refuel."

Agree with ionised and reddit_clone (below). I'm an introvert and I am definitely not shy, nor are my thoughts 'self centered'. It's simply that it takes more mental energy to engage with those I don't already know.

[edit] to clarify to whom I'm agreeing.

I am pretty introverted. It's not that I'm shy, it's that conversations take a lot of mental energy for me, it's exhausting.

Except it isn't. I suggest you do some reading and educate yourself.

No psychologist worth their salt would define an introvert that way.

There a various definitions, but the one I like is: introverts exhaust energy while around people, extroverts recharge.

It's only one of the definitions. If anything, it's the common one instead of being the scientific one.

http://www.dictionary.com/browse/introvert says:

"introvert

noun

1. a shy person.

2. Psychology. a person characterized by concern primarily with his or her own thoughts and feelings (opposed to extrovert ). "

No (2) doesn't sound right. It makes it sound synonymous to 'self centered', which I am sure most introverts are not.

Your "own thoughts" don't have to be about yourself. It just means you're paying less attention to what other people think or feel.

(edit: added "don't")