He was going to tease her about how they were still her friends, but he understood what she meant - it wasn't the same now that they were older, and all living elsewhere, instead of just being at Hogwarts. Heck, it had taken him a month just to brave the stairs to come up and see her.
"Odd," he said quietly. "That times of such danger should bring people that close together, and times of peace should bring them apart. I'd imagine that if things grew difficult again, similar relations would develop between the students and professors here. Perhaps we would rekindle old friendships that had died..."
For a moment, he fancied that if there were another war, that he'd somehow be called on to help out with it, like before - but he supposed that was silly of him. Harry likely had other people that he could call on, and wouldn't really have use for a Herbology professor. He smiled sadly.