A customer is just that: a customer. They come, they give you their money, they leave, you forget about them and you never see them again.
You never see them again. That's what hurts, when you do remember them. Sure, you can have recurring customers, you may grow to be a bit fond of your regular buyers, but after a while, after some point, they move on, and the way of life continues.
Sometimes, though, you can't forget a customer. It happened to me, that way. I'm an innkeeper. I have been for as long as I can remember. I see a variety of faces, and get to know them – somewhat. Not really acquaintances, not friends. I don't even know their names. And normally, I don't care. I learn their faces, so I can recognize them while they're here, and maybe pick up a few quirks – the night elf who can't stand it when I flip coins for hours on end, the orc who won't tolerate any humans in his corner of the inn; you know, important things about customer satisfaction, because I'm a nice fellow like that. But I never bother to really get to know them. They are the adventuring types – living lives of action, settling for a few weeks in one place, slaying monsters, meeting people, moving on; the lifestyle I, myself, would have – were I able to make as much of a profit there as I do here.
I accept that one day, they won't come in, and I won't see them anymore. That's part of why I don't try to get to know them. Sometimes I can't help it. And I regret it.
There was a beautiful troll – I never knew her name. She stayed at my inn for three days, and then I never saw her again. She had golden hair in a high ponytail, teal skin accented by purple-dyed leather, fangs, and a very goblin-like face, only prettier. Her cackle was charming. She would break up fights at the bar and joke around warmly with the other guests – she was good for my profits and good for my soul. I grew to enjoy seeing her, though I didn't really speak to her much, just a "your room is ready, lady," or "would you like something to drink with that tiger's liver?" But she would smile when I spoke to her, and I smiled too.
She paid her rent on the third night, and on the fourth morning, she slung her bag over her shoulder and left, off to another adventure in some distant land. I never saw her again.
For a long time, I wished and waited. I advertised better services and offered a (slight) discount for trolls, in foolish hope that she would return. Sometimes, I still do – I guess it's a way of remembering. Every time a female troll enters my inn, for a brief moment, I think that maybe, just maybe, she's stopping by on her way through. But it's never her. And in the back of my mind, I know I'll never see her again.
But I also know… that I love her.