Easy As Rolling Off a Log

Etymology:

• This idiom is originated back from the United States in the early 19th century. This idiom was first used; when logs were thrown down from the forests to the rivers to send them to the lumber mills. Men decided competitions to check who could stand straight on a floating log till long duration. Most of them fell into the river as it's very hard to remain standing on a floating log and very effortless to fall off one.