The player is just a guy that decided to play a game called Hollow Knight. Now the player went to Greenpath and stumbled into Hornet (the user). The player doesn't know that Hornet is sentient so if he'll say something to her and Hornet will say something that feels like a response to what he said he will be weirded out because normally bosses aren't sentient in games. The Knight is actually just a human guy who is playing the game, so he's not actually The Knight, he's just playing the game.