At various points throughout Michael Frayn's novel Spies, reviewed here a few days ago, the narrator Stephen Wheatley makes comments like "Everything has changed once again, and changed forever" and "The world has changed yet again." Profound things are happening in the life of the boy he was when these events occur, and each one restructures the world as he knows it.
I am inclined to believe that even seemingly minor actions can and often do restructure the world. Perhaps the flapping of a butterfly's wings in Brazil cannot really cause a tornado in the American Middle West, or whatever "the butterfly effect" supposes, but I do believe that small things can have widespread consequences. This idea is explored in the German film Run Lola Run. When Lola runs around rather than through the middle of a group of nuns on the street, it impacts differently both her own life and the lives of the nuns. Little things really do mean a lot.
Several years ago my wife and I found this to be dramatically true twice during a drive to Toronto. While on Interstate 90 in New York, we were passed by a flatbed truck carrying a weed trimmer. As it was going around us, the truck hit a bump in the road and the trimmer flew up into the air. When it came down, the truck was no longer there. It hit the pavement and bounced into our lane, barely missing us. Had we been traveling only slightly faster, it would have hit us.
Hours later as we approached Toronto on the multi-lane Gardiner Expressway, I glanced into my rear-view mirror and saw a red sports car careen from one side of the highway to the other and back again, somehow not hitting anyone (that I could see) despite the rush-hour traffic. Had we been moving only slightly slower, it would have struck us.
Our actions have ripples that change the world, or at least our own little part of it. Meanwhile, our lives are being rocked by the ripples caused by the actions and decisions of others. Just living is a heavy responsibility.