He's not supposed to be here. I am missing some crucial piece of information that would explain why my middle school science teacher just rang me up for a golden-yellow wool sweater at the mall. If he recognizes me, he's made no indication that he does. He asks me if I want a receipt. I try to focus on the question and not on the fluorescent light reflecting from the top of his bald head. That familiar distraction. I tell him no, thank you, and turn to leave without another word. I had been one of his better students, but evidently that is not enough for someone to remember you.

Theory I
All of the people that inhabit my world are actors, including you, dear reader. They move from role to role in a way that attempts to conceal the fact. On this day, Mr. Birnbaum was no longer Mr. Birnbaum, he was, according to his name tag: Jason. It's entirely possible that Mr. Birnbaum's first name was actually Jason. I did not know the first names of any of my middle school teachers. The directors in the play of my life remembered to change his name, or at least hide his last name, but they forgot to change his appearance: bald on top with a band of gray hair cupping the sides of his head. Bushy mustache. He seems slightly happier, which I would not have guessed. Then again, he may have been talked to by the manager, letting him know he needed to greet customers more cheerfully. The manager is of course not a real manager, but a director playing a manager.

Theory II
At some point over the past twenty years, I switched dimensions. I do not claim to understand the mechanisms by which this could have happened. But for the sake of this theory let us posit that there exists a wormhole in the bathroom of the gas station Subway between Bakersfield and San Francisco. This is just as likely as any other possible explanation. Previously, I was in a dimension where Mr. Birnbaum was a middle school science teacher, but now, having used the bathroom at a gas station Subway, I find myself in a dimension where he works at a clothing store in the mall. He is bald in both dimensions.

Theory III
He was fired for inadvertently showing the students porn, and one of the few jobs he could now get, being barred from ever teaching middle school again in his life, was working at a clothing store at the mall. I do not like this theory because I liked Mr. Birnbaum and do not want to believe he would do something like this. It speaks to a fear I have of being stuck working retail, in a position where I have to pretend I am happy for eight hours a day when nothing could be further from the truth.

Theory IV
He quit because middle schoolers are terrible people. Specifically, it was something about my behavior in his class that led him to quit. One of my smart aleck comments was the one that broke the camel's back. I drove him to leave a job he once thought he loved, to do anything else, which in this case turned out to be retail at a clothing store in the mall. The parameters of our interaction forbade him from letting me know how he really felt about me: that I had ruined his life, that I was responsible for him quitting teaching, which had led to his wife leaving him, which had led to him becoming an alcoholic, and made it so that his daughter, who grew up idolizing him, now refuses to speak to him.

Theory V
Birnbaum cloned himself.

Theory VI
Mr. Birnbaum, a.k.a. Jason, is passionate about mall fashion and had been biding his time as a middle school teacher until he could land a job at one of his favorite clothing retailers. He had fallen into teaching middle school science because his father was a science teacher and so it felt only natural that he too would teach science. However, deep down he hated this, and on the day his father died he gave notice, freeing him to pursue his dreams. He has been so happy since pursuing his dreams that he does not remember any of his students, myself included, whom he resents. They are a monolithic symbol of his repressed desire.
   
Theory VII
Jason is a man who happens to look exactly like Mr. Birnbaum but bears no relationship to him whatsoever. They live in the same city but have never met. Occasionally, someone will say something like, I thought I saw you at the mall the other day, was that you? And Mr. Birnbaum laughs and says no. Or they say to Jason, gosh you look just like my middle school science teacher, did you ever teach middle school science? And Jason laughs and says no.

There are many more theories, a whole book of theories that I have written, including the most likely theory in which we both remembered the other but were too shy or uncertain to say anything. Men do this frequently—pretend to not know someone. It is possible that he was embarrassed. I myself have felt embarrassed working in retail. If you have a master's degree there is a misguided expectation that you are somehow above working in retail. Nevertheless, it's possible that I did him a favor and that he misses teaching, he does not want to be reminded of the past life where he taught pre-teens about tadpoles and evaporation. "Come see us again," he says as I approach the metal detectors. I won't be. Besides, they pay him to say that. It is too painful to think you know someone and then discover they have changed, or worse, were never really the person you thought they were.




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