Spock had experienced emotion before. Most he didn’t like the feeling of, so, naturally, he blocked it all out. But something about when you walked into a room made his head spin. As a creature of logic, he couldn’t figure this out. But he is half human. And in the back of his mind he had an idea of what was happening, but he wouldn’t let himself come to terms and face it. It’s just the way your eyes light up when you smile, and how sweet and determined you are; he is even puzzled at the fact that he thinks about these things.