Headstone’s position on Lizzie’s potential as a student changes abruptly. The one thing that changed is that he saw Lizzie in person, and this passage strongly implies that when Headstone talks about a hypothetical man marrying Lizzie, he means himself. Still, Headstone seems too proud to admit that he wants some “beneath” him like Lizzie, which is why he then decides to educate her and make her “worthy” of him.