Smiling is sadaqah, according to the Prophet, and it is reassuring to see it making a difference whenever it is used. Whenever I am going out I ensure I am not without it; it has gotten me out of many a fix. I am not a good driver and for most of my adult life I have not owned a car. On the behest of some well meaning friends I finally purchased a car and endangered many lives. So far by sheer luck I have avoided serious casualties, though I have inconvenienced many. Whenever I make a life threatening mistake on the road, I give an embarrassed smile, often people are generous enough and accept my apology in their stride, but on rare occasions I have been the worthy recipient of expletives. I can easily say that most often the response has been benign and the worst is verbal abuse; my favorite though is a shake of the head (those who have seen it know what I am talking about) – this I get from pedestrians or cyclists. Pakistanis are generally very kind and when you apologize they will be too happy to forgive.
A really clever friend of mine once told me about the chaos effect and the butterfly effect, I cant help but think that a smile may have just such an effect, and a frown or a harsh word just the opposite. So … smile.