Leaving is always hard. Leaving somewhere you want to stay is a difficult thing to do.
What’s worse, though, is being left behind. It’s a feeling I’ve always hated, whenever I’ve had guests. The emptiness of the house, of the room, after people you’ve wanted to spend time with have gone away. If you’re the person leaving, you have travelling to do, things to take your mind off the departure. If you’re the person being left, you have nothing to help you.
Because of that, I can always sympathise, with anyone in that situation.