force of habit (countable and uncountable, plural forces of habit)
- (idiomatic) an act that has been repeated to the point where the performance of the act becomes automatic
- "Only force of habit will explain why people today do honor to Christopher Columbus." - New York Times, 1937
- 1900, L. Frank Baum, The Wonderful Wizard of Oz
- The Tin Woodman lay down on his bed from force of habit, for he remembered when he was made of flesh; but not being able to sleep, he passed the night moving his joints up and down to make sure they kept in good working order.