Every Face in a Different Place

In our lives, no matter how short, or how long, we will meet hundreds upon hundreds of people.  Now, I use the term "meet" very loosely.  You meet every customer that walks up to your register and orders a milkshake.  Every operator in india that takes his or her sweet time to actually help you with your technical problem on the telephone (after putting you on hold 50 gazzillion times to deal with lame elevator music), and every salesman that comes knocking on your front door.  But you can't know from a handshake, who they really are.  Handing them back their credit cards and wishing them a nice rest of their day really doesn't constitute as sitting down to coffee and dipping into their personal lives.  So do we choose those that we become close to?  Are we really the selective ones, or do they choose to know us?  Maybe there isn't any actual selective-choice-making happening at all.
If you walked up to an elderly couple in the mall and asked them how they met, I'm sure you'd get quite the story.  The point is, that it seems they've been together since dinos walked the planet, and for some odd reason saw something in one another that kept them together until Edison created the light bulb.
So the question is: How did two people who are so perfect for each other, manage to find each other among everyone they've met on a daily basis, in the first place?  What made that person different from every other face in the crowd?  How did they just manage to cross paths and decide to get to know one another?
Okay that was more than one question, pardon the typo.  But you see my point.
Some will argue pure coincidence, while others will defend fate.
I like to think a little of both have something to do with it, along with some genuine "purpose" thrown in.
Sure, there are people that I've met that I don't really care to know.  But then there are some that, without them, I don't know how my story would have made it this far.
Global is another concept.  What about those people all around the world?  We often forget that there are other countries, and that people exist on them.  Most of the time we forget that anything even exists outside our hometowns.  Will we ever meet them?  Will we ever get a chance to learn their stories, or be given the chance to let them change our own?
While we may never encounter everyone in our lifetime, all of the people we "meet" put together add up to every different kind of person one could possibly need to know, to get them through their worst times and put them through their best... Now how does that work out?
Coincidence, fate, or sheer dumb luck... I think it's a pretty incredible concept... One you can mull over while you sit at the table in the coffee shop by yourself because your friend choose not to show up on schedule for personal-life-dipping time :D Happy mulling.