by force of habit
Because one does or has done something habitually. Used to describe an unconscious mistake that results from following one's routine rather than choosing the correct action for the circumstances. After living next door to Anna for 50 years, I call our new neighbor "Anna" by force of habit.
by force of habit
owing to a tendency to do something that has become a habit. After I retired, I kept getting up and getting dressed each morning by force of habit.