How I know I'm an extrovert

I get really restless if I'm not hanging out with other friends for extended periods of time.
I get headaches if I go out exploring on my own, especially if there are huge crowds everywhere.
Probably because all my thoughts just bounce around inside my head with no room for escape.
I think extroverts are some kind of a vampire, who feed off the energies of other people. Like, just being around friends and participating or observing social interactions, it's refreshing.

I could never live alone with no friends or family at all to share experiences with.
Also, there just aren't enough articles on how extroverts get exhausted when being alone for a while.