sometimes people surprise me

I was out shopping at Hecht's for something suitable to wear for interviews. The cashier asked if I had my additional 15% off coupon, which I'd left at home (not realizing I'd end up at Hecht's). I said no, and the woman who had been in line in front of me came back and said "Here, take one of mine." and handed me an appropriate coupon. Isn't it sad that the first reaction when someone randomly does something nice is shock?