I've got a filter for most icky people. If I don't like someone, I usually forget their face, their name, and everything about them. I've written about some of them on this blog that, for whatever reason, stayed with me, but not by their real names ... I couldn't recall those for love or money.
When I waited tables or tended bar, I could remember what someone ate or drank even years after they ordered it if I liked them. If I didn't like them, I could forget I had a ticket hanging, I was that eager to make them disappear. My rose-colored glasses kept me from hanging on to bad energy, but they also kept me from recognizing some of the same bozos who came in more than once to stir up the same trouble. "EVERY time I come here the food is LOUSY!" was one I should have braced myself for, but I would only realize I had heard the same words from these people after they ordered, ate all their food, and tried to get out of paying for the third or fourth time.
Some of the people I really liked weren't necessarily good tippers, and some of the ones I despised might tip me fairly well. The money didn't have that much to do with my feelings, even though it was hard not to take it personally when I'd done everything but crochet their napkins for them and I made a lousy two bucks on a four-top. I had some customers that were just a pleasure to see; I liked knowing they were on the same planet. There was a beautiful elderly woman who attended meetings with a couple of different groups that I remembered the second time I saw her. I said, "You look familiar to me" and she smiled and said, "Oh, but I am." and then she winked. I think I blushed all the way to my toes, but it was the sweetest moment, and I'll probably always remember her. There was another guy I ran into in a supermarket years after I'd worked at a restaurant where I was his waiter. He said, "Hi" and I instantly thought, "Corned beef hash and eggs over hard. Rye toast." 25 years later and I still remember.
If I had a bad shift, and I wanted to forget the whole thing, I would spend my tips before I got home at another restaurant, a bar, the grocery ... it didn't matter, so long as that tainted money didn't come into the house with me. I think that's what helped me start fresh the next day. It didn't protect me from being hurt again, 'cos I don't think I've ever been very good at separating some people's need to lash out at strangers and my own reaction to being attacked. I worked in the dining room of a hotel that hosted assertiveness training classes where attendees were instructed to practice their assertiveness skills on their waiter during the lunch break. I blew a lot of cash on days I waited on them. Somebody wasn't doing a very good job of explaining the difference between "assertive" and just plain "ass." Maybe my being available to be their punching bag kept them from beating their wife or kicking their dog. I like to think some good came out of it.