I wouldn't beat yourself up over it - in states where full service isn't mandated by law it is expected that you tip your attendant when you go to a full servic

I wouldn't beat yourself up over it - in states where full service isn't mandated by law it is expected that you tip your attendant when you go to a full service station. I worked at one in PA growing up and most of my wages were from tips, sort of like being a server.