“How about I leave you my number?” I’m concerned that if there is a mistake the waitress might end up being asked to pay for any shortfall. “If there is a problem, then you can call me, and we can sort it out.” She takes the number but assures me it will be unnecessary. “Sometimes folks do this sort of thing…pay it forward, or pay for a stranger or whatever meme is doing the rounds. I wouldn’t worry about it.”