I am friendly with a former boss of mine, now retired from the world of work. I arranged to meet her for lunch on a Friday when I thought I would be quiet at work but it was not quiet and I scooted out to meet her and arrived late and had to leave early. I then realised that I had left my wallet back in the office and she had to pay for my lunch. The final indignity was that she had bought me a box of chocolates for the children and I forgot to take them with me so she dropped them round to my office later in the afternoon.
I think I probably owe her a nice lunch.