Think about the idiom "out of your depth": you're thrashing around, not because you're mad at the ocean. What he's doing, in this sense, is defensive: he isn't really mad at me, he's just out of his depth. And I'm not mad at him, either: he said, "it's been nice knowing you", and my reply was, "You still know me, you just don't think it's nice anymore" —followed by a winking face. ;-)
