“His destiny was to be elusive of social or religious orders. The wisdom of the priest’s appeal did not touch him to the quick. He was destined to learn his own wisdom apart from others or to learn the wisdom of others himself wondering the snares of the world.
The snares of the world were its ways of sin.”
James Joyce, A Portrait of the Artist as a Young Man (New York: Oxford University Press, 2008), pg. 136
I believe this is the moment where Stephen realizes he wants to be an artist.