Today, one of the graduate students I was mentoring asked me what target audience to have in mind when writing their first research paper, which combined ideas from two different mathematical fields - for instance, how much detail to spell out for a lemma which would be basic and well known to experts in one of the fields, but not the other. After discussing some hypothetical readers with strengths in one field but not the other, the framework that seemed to generate a "lightbulb" moment in the student's head was the suggestion to take as the model reader a version of the student's past self from about twelve months ago when first learning the subject, and to try to write to specifically address any confusions that the student had that could have had been resolved if only there was a text that had explained these basic points clearly. It was clear that the student had several such points come to mind immediately, and almost instantly had a much clearer plan for how to write the paper.