Take a metal coat hanger and straighten it. Hold a 10 inch straight section so it points up in the air. Holding the bottom still and using the other hand to bend it to the side, move the end 1 inch then release it. What happens? Repeat this with 2 inches, 3 inches, etc, until it does not return to the starting position. What happened to the coat hanger between the points that it would return and when it did not return?
