When meeting somebody new, it's like looking at a map of a foreign city. It takes practice to memorize all its streets and find your way in it. Every corner looks new, every restaurant around the corner, every crossing, every turn. Then you live in the city for too long and you know your way almost unconsciously; it's too familiar that you forget that you once lost your way in it. The city grows on you, it becomes part of you. The smells, the noises, everything that makes a city breathe will be imbedded within you.
Then when you leave the city, you're always afraid that by time the memory of it will get stale. That the city that you've once known so well is no longer recognizable. Would anyone believe that the Cairo of 50 years ago is the same city?
Maybe some shops have closed down and others have opened. Maybe billboards infested the streets. Maybe the streets got dirtier, the people louder, the drivers bolder.
And that is always the fear when you're about to part with someone you have come to know so well.
You wonder that maybe in many years you will meet again. You will see traces of your past somewhere inside the person, but you will no longer recognize the person.
The routes you have strove to learn so well have become clogged in your memory. And that second you realize that the person is forever lost. Sometimes it's sad, yet at other times you know you have also been unrecognizable to them and think "that's just life!"
Prior to losing you always hope that what you have transcends the mere boundaries of the physical world. That there's a much deeper connection; that of the soul, the one that could never be shattered to pieces by time.
Time would be merely an ellipsis, nothing more.
Memories are never blown away immediately. The tick of the clock eradicates them slowly, like water washing over stones. By the time their shape changes, you no longer pine for them.
"That's life!" you would say and walk away.