There is a curious incident in the story of the sale of Joseph. When his father sends him to check on his brothers, he meets a stranger who tells him that his brothers have moved on to Dothan. Without that encounter the rest of the Torah would be entirely different. Joseph would not have been sold, he would not have interpreted Pharaoh's dreams and the Exodus would have been something else entirely. So too with most of history. Seemingly unimportant encounters wind up having important effects. God prefers to act subtly most of the time, so one can have a large effect on others and on history without being aware of God's hand.