Boy: Hello Gregarious, you look good today!
Girl: Thank you Greg!!
Another way of saying somebody is people needy, and has a herd like group mentality.
Most people are not really gregarious, most people like a balance of space and company. People who claim they are gregarious all the time are full of shit, and usually have lots of people around them at all times as a crutch, since on their own they're weak people.