Answer:
Auggie considers himself the “old moldy cheese” because he feels that his classmates avoid him and treat him as if associating with him would ruin their social standing. This is similar to the “Cheese Touch” in Diary of a Wimpy Kid, where touching a moldy piece of cheese on the playground leads to social ostracism.
It’s a metaphor for how Auggie feels isolated and rejected by his peers due to his appearance
