There is always an ex who will continue to affect you, no matter how hard you try to forget the impact he has had in your life.
Most of the time, you don’t think about him. He occupies a dusty corner of your mind, and you’ve shelved any memories or thoughts of him behind matters of greater importance — matters that mold your now and your future rather than revisit your past.
Sometimes, someone will casually mention his name in conversation or bring up a story that involves him. Sometimes, as you sort through your closet, you will inadvertently find a piece of clothing that belonged to him —a sweatshirt or a tee-shirt you once wore with fervor and forgot to toss into the black, plastic bag that you used to trash all his belongings.
And you will think about him, but you will feel nothing more than a fleeting pang of nostalgia for a connection you once had but will never have again.
When you begin to remember him, you will force yourself to stop. And you will call the guy you’ve been seeing for the last several weeks, who is nice and handsome and occasionally funny and possesses every quality that should appeal to you except for the ability to render you weak at the knees.
You will head over to his apartment and spend the night, watching a movie whose every line you have already memorized. You will rest under his embrace, which you are slowly allowing to become more familiar.
Eventually, however, you will run into your ex.
You will run into him several months — almost a year, actually — after the last time you saw him, while finishing an assignment at an out-of-the-way bookstore that you don’t usually frequent. At the exact moment you look up from the pages of reading you were supposed to finish for class last Tuesday (life and episodes of Mad Men never fail to get in the way), you will see him walk in behind a group of his friends.
It will feel as though the cosmos are playing a cruel joke on you.
“What’s wrong?” your friend will ask you, noticing that you’ve started to redden from the neck up and that your hands have begun to shake, splashing drops of coffee from the cup that you are gripping tightly as a means of calming yourself.
She will not have noticed his presence, and you will not bother to tell her.
So, you will shake your head and try to focus on the papers in front of you as you steal peripheral glances at him, knowing — all the while — that he does the same, out of the corner of his eye.
You will notice that he’s cut off most of his hair and that he seems a bit more muscular than when you dated. You will realize that he is wearing those raggedy jeans — more holes and frayed edges than actual denim — you always threatened to throw out but never did because you knew how much he treasured them.
As your friend scratches at the assignment in front of her with no loss of concentration — oblivious to how quickly, how frenetically you’ve begun tapping your fingers against the table — you will struggle to decide if you should get up and say hi.
You will wonder if that is what mature adults would do. Would that indicate that you are okay? That you are over him, the situation? Over it? Over whatever situation transpired between you two — an amorphous glob of tears, sadness, and anger that you can’t characterize even months later?
Ten minutes will have passed since he and his friends walked in before you will set down your pencil and slowly ease yourself up from your seat. He will have made his selection, choosing a book or two from the aisles you traversed a few hours earlier. You will realize that this is your chance to make amends, and you will decide that it would be silly to pass this up. That you have long passed the process of letting go. That you can speak to him normally again.
He will not turn as you begin to make your way over. Instead, he will collect his change from the cashier and tuck the book he’s just bought under his arm. He will start towards the exit, and you will stop walking towards him — rooted in stasis as you watch him leave.
After all, bygones will never really stay bygones. 
