you are told the sad and heart-rending tale of a wronged woman—to you, a chaste knight-errant—and about a woman!
That's why he was smirking so suspiciously during Aglaya's recital of the poor knight. He understands this better than any of the cast and he wasn't even here for most of it.
Also, Radomsky just spelled out Myshkin’s main reason for loving Nastasya so much to all the readers. The poor knight only wanted her to be redeemed.
