Any time I have a longer conversation with a customer I liked, they either end up being endlessly awesome, or completely awful. Never "huh, I guess that was about what I expected."
The people who go out of their way to compliment me/my drinks/my behavior more than once are always assholes. Always. They like me because I bend over backwards to make them happy. They are friendly to me because I give them what they want. The second something doesn't go their way they turn on me like a fuck*ng wild dog.
This one lady, though, her name is literally Joy. Every time I talk to her it brightens my day. She has adorable kids and always sticks around the extra thirty seconds to make chit-chat. And she is hilarious. I never know how to tell people like this how much I appreciate them without going overboard. I don't need every customer (or even most) to have this kind of interaction with me, but every once in a while it happens and makes my whole day better.
I am an over-emoter.