Good post, and I am sure there would be many to share some of their experiences too...here's mine:

Nearly two weeks ago, I was at Gharaffa, and while there, I went to a grocery store to treat me some chocolate and a cola. A Qatari along with his little daughters were also grabbing chocolates and juice as well. As I was about to pay for my stuffs, the gentle Qatari came up to me and said..."Consider your stuffs paid, you don't need to pay up". I was surprised at this, cause it's the first time for me. I insisted that I already had my money at hand to pay, and really, I wouldn't need this one, but the gentleman held his stance. Later on, the shopkeepers had told me, whenever he's out with his family and comes to this grocery shop, he always ends up paying for his plus the rest waiting in the queue because of him. I couldn't say anything else above that, but just thanking him for it...