I can connect to quite a bit of it. The things that stuck out to me were the special interest (the snow) the familiar routine (the postman) and the general lack of understanding and acceptance which leads to people becoming adversarial.
I looked up the written version of the story and read it. It was the masking that really stood out to me above all else:
Silent Snow, Secret Snow at FullReads
"All one could do was to laugh embarrassedly, pretend to be a little ashamed, apologize, and take a sudden and somewhat disingenuous interest in what was being done or said."
"It was as if he were trying to lead a double life. On the one hand he had to be David Jones, and keep up the appearance of being that person-dress, wash, and answer intelligently when spoken to"
"But how then, between the two worlds, of which he was thus constantly aware, was he to keep a balance? One must get up, one must go to breakfast, one must talk with Mother, go to school, do one’s lessons- and, in all this, try not to appear to much a fool. But if all the while one was also trying to extract the full deliciousness of another and quite separate existence, one which could not easily (if at all) be spoken of-how was one to manage? How was one to explain? Would it be safe to explain? Would it be absurd? Would it merely mean that he would get into some obscure kind of trouble?"
"And at school, how extraordinarily hard to conduct with success simultaneously the public life and the life that was secret."
"Yes: it must be kept secret. That, more and more, became clear. At whatever cost to himself, whatever pain to others-"
"It was desireable of course to be kind to Mother and Father, especially as they seemed to be worried, but it was also desirable to be resolute. If they should decide-as appeared likely-to consult the doctor, Doctor Roberts, and have David inspected, his heart listened to through a kind of dictaphone, his lungs, his stomach-well, that was all right. He would go through with it. He would give them answer for question, too-perhaps such answers as they hadn’t expected? No. That would never do. For the secret world must, at all costs, be preserved."