1. The title and the “sounds like a middle school subject” part of the prompt seem unrelated — surely we’re not looking for a teenage actor. But they both have words that refer to a key thematic element.
2. The theme entries themselves don’t matter. But their clues do.
3. As in many metas, these are cover-two clues. Each can apply to another entry in the grid, but . . .
4. Only after that entry has been slighty altered. That alteration derives from the common idea mentioned in Nudge 1.
5. you find those alternative entries and proceed in the usual way, you will get gibberish. Again, you have to apply the common idea.
6. Or you could just go to the Internet and look up the date of the puzzle (it’s repeated in the intro) and find that it is designated as a special day.