Them being different is apparently news to Vincent, who perks up in surprise when Irahl agrees so bluntly and easily. Then again, Vincent's entire method of relating to other people is to find the ways they're similar and lean on those as hard as he can. He has a hard time understanding how to be when he can't connect to someone else.

"My..." He reflexively lifts his hand to touch the closed lid of one of his eyes as attention is drawn to them. Ruefully, he says, "That's just me bein' an idiot..."

It wasn't a choice. At least, not so much that Vincent really equates it with self-sacrifice. But he's very biased, in that regard.