Chronicles of Narnia is christian allegory? I never made that connection.
If you were to read them again now, I'm sure it would be very obvious to you.

Very much so.

When my children were small, I made a practice of reading all the books that they were reading. Intending to given them those Chronicles, had the foresight to read the entire seven volumes first. The parable doesn't become evident until the final volume, but there it is striking.

Expressing no objection to proselytizing literature, I did and do think it quite a bit forward to proselytize to children in a form disguised from their parents.