Don't get around much anymore

I know you all think I'm about to tirade about my own hermitity (yes, I coined a new word!)...but you would be wrong. I'm about to tirade about those people who are tireless networkers.

They are those people who know everyone...they just get around! They are ubiquitous! (I love when I can use that word!) At uni yesterday I saw someone about 5 times that day always with different people. If someone happened to be following me around and taking note of the people I was seen with, I think you could count that number of people on one hand.

I have this shake-my-head-in-wonderment reaction to them, especially when I myself am more than content to find a small group of buddies and stick with them.

Do you think it's:
a) A conscious thing (something they make an effort to do)?
b) A personality thing (as in, they have a propensity to go out and meet people because they're extroverted types of people)?
c) A happen to be in the right place at the right time thing (as in, they just do a lot of stuff, and by virtue of that they can't help but meet people)?
d) A charisma thing (as in, people are drawn to them, so even if they were sitting in the corner of a foodcourt having lunch by themselves, they'd still end up meeting people)?