By James Clear
"Maxwell Maltz was a plastic surgeon in the 1950s when he began noticing a strange pattern among his patients.
When Dr. Maltz would perform an operation — like a nose job, for example — he found that it would take the patient about 21 days to get used to seeing their new face. Similarly, when a patient had an arm or a leg amputated, Maltz noticed that the patient would sense a phantom limb for about 21 days before adjusting to the new situation.
These experiences prompted Maltz to think about his own adjustment period to changes and new behaviors, and he noticed that it also took himself about 21 days to form a new habit. Maltz wrote about these experiences and said, “These, and many other commonly observed phenomena tend to show that it requires a minimum of about 21 days for an old mental image to dissolve and a new one to jell.”
In 1960, Maltz published that quote and his other thoughts on behavior change in a book called Psycho-Cybernetics. The book went on to become an blockbuster hit, selling more than 30 million copies.
And that’s when the problem started…”
Read the entire article: How Long Does it Actually Take to Form a New Habit?