The Butterfly Effect states that one minor and seemingly unrelated change in one state can have a widespread impact on a future state. In other words, the small choices and decisions you make today might not seem significant or life transforming, but over the course of years a culmination of the small and seemingly insignificant decisions you make will significantly alter the course of your life.
This law is derived from the example of how the flap of a butterfly’s wings on one side of the world can stir up a hurricane on the other side of the world. It’s not necessarily the flapping of the wings in isolation that triggers the hurricane, but rather the flapping of the wings leads to something else, that subsequently leads to something else, and something else still that progressively triggers the formation of the hurricane.
Small things have a big impact over the long haul, just like your small daily choices have a significant impact on the course and direction of your life.
The Butterfly Effect is part of the wider arching Chaos Theory which is the science of surprises, and of the nonlinear and unpredictable. It basically teaches us to expect the unexpected.