He doesn’t, in fact, know who Anna Karenina is. His first thought is that Bucky is mocking him somehow, which doesn’t entirely mesh with his first impression of the man.

“I’m not old.” He says it with the indignant fury of a young adult, folding his arms across his chest. He’s certainly not a child — perish the thought! — but he isn’t some sort of ancient man. “Just because I’m from a long time ago doesn’t mean I’m really…” (he pauses to do the math) “…one hundred-twenty-seven.”