Love. Harry barely had any true notion of the idea until just recently. It was always something he was vaguely aware of, something he saw in others, but could never quite grasp in himself. Even when his mother had told him he was in love with Hermione, he didn't really believe it at first. He'd have known, surely? He'd hardly been out of her company for seven years, so any urge to take their relationship to something more than just best friends should have been right there in front of him, shouldn't it?