Random passerbys in our lives and the contemplation they cause.. :P

So I spent the past three days doing testing, go me! lol. I'm leaning more towards engineering this fall I think. I want to look more into the types, though I have it narrowed down to three. Anyways, I was struck at the end of todays work with how we meet those random people at times. The ones we converse with, share our lives with as if they were a good friend and then whatever project or thing you were working on that brought about said introduction is over. And you realize later that day that you won't see them again most likely, except perhaps by luck or chance.
Strange to think of how we become friends of a sort with people and then move on days or weeks later. Never thinking to get contact info or anything of the sort to continue the aquaintanceship unless by chance you remember quite a bit later after all is said and done. A few months later you might even find yourself asking, I wonder how such and such is doing. Then pause a moment in contemplation and move on thinking nothing more of it.
I find upon closer inspection of such happenstance that humans can be quite the fickle creature. Ever in search of change. New things, new ideas, forgetting in this quest that perhaps we should stop and look a little harder, try to keep touch with what we've seen and done, people we meet by random design. These things we leave behind in the dust and cobwebs of memory, thinking it of no real importance. But if we were to take that chance, retain and look a little harder... perhaps we would have found something worthwhile later on.... a lifelong friendship, an opportunity led to down the line brought about by forgotten knowledge... and yet, we shall never know cuz on and on we rush... never even realizing we do so.