Have you ever had a complete stranger pay for your meal?

So last night my girl and I went out for dinner, we ate and asked for the bill, it took them 20 minutes to figure out where our bill disappeared to, only to realize that it had already been paid for by these two bikies that I had briefly smiled at for a split second. They didn't talk to us, they didn't mention they had paid it, they didn't expect anything in return, it was so strange. I've had strangers pay for my meals before but they usually ask for my number or a date or something. It was just the two of us but we ordered $120 worth of food.