It's a good thing you don't have to say "bless you" when people cough. It's such a hassle to offer strangers on the street and friends on the couch constant blessings for their sneezes. In fact, it's unfair that the onus is on the person who didn't sneeze to say "bless you." It should be something the sneezer is in charge of. Instead of saying "excuse me," they could simply say, "bless me," and then we'd have all our bases covered. I'd lead a charge against saying 'bless you,' but people would just think I was being rude.