We had these times, riding in the back seat of our family car, when we would look at each other and burst into laughter, for no apparent reason. Not the kind of smallish laughter, but that kind that makes you cry for no reason other than the fact that your sides hurt so bad that that is the only thing you can do. After a minute or two, Mom would get pissed, or try to at least, and turn around and tell us to be quiet. Only, she couldn't do it, she started laughing too. So, she would turn around and try to stifle her laughter while my father would look at her from the driver's seat. Soon, she would just be in hysterics and, of course, Dad had to get in on the fun. This is the best way to start out a family vacation.