The 21-day Myth

The 21-day MythYou’ve probably heard it takes 21 days to form a habit or to learn something new. Our brains love precise answers like this one because it seems so accurate. We latch onto it as if it’s true, since it takes fewer brain resources to just accept the answer instead of really thinking about it. When we continue to hear it repeated by people whom we look up to, then we begin to take it as a universal truth.

In spite of all that, let’s stop and think about this one for just few more seconds.

    • If your 2-year-old touched a hot stove, do you think he would need to touch it for the next 21 days to learn to modify his behavior? No. That habit got formed in less than a second.


    • If you just got a brand new Lamborghini Murcielago Roadster, are you going to need 21 days to force yourself to drive it all around? LOL, I don’t think so. I think you’ll be sleeping in that puppy the first night.


    • If you cooked yourself broccoli for a year, and you hated broccoli but wanted to force yourself to eat it, how many days would that take? Probably more than 21. Probably more than a year.


  • If you were a gambler, smoker, or drinker, how long would it take for you to change that habit?

It’s easy for our brains to take the shortcut answer of 21 days. We use fewer resources that way and have the problem solved. The problem is that 21 days is a nonsense answer that doesn’t mean anything.

How long does it take you to learn something to the level of a habit? It depends on your motivation, your age, your brain power, task complexity, and meaning. Repetition is only one of many learning variables.

In her book “The 24-hour customer,” my friend Adrian Ott from right here in Silicon Valley describes the origin of this myth. A book written in 1960 by a physician stated that amputees took 21 days, on average, to stop reflexively attempting to use their missing limb. She got this story from an Internet site PsyBlog (, which I haven’t validated, so I have no idea if this is true. The web page goes on to say that research was done in 2009 by University College, London that measured various tasks from drinking a glass of water to running and found that the habit formed after a mean of 66 days, with a range of 18 days to 254 days (Lally, et al, 2009).

OK so why does this matter and how is this going to change my daily life? It matters when you supervise people, teach children, start a new job, communicate with your spouse, help someone learn something, or want to change a habit yourself. Want to move into more of a success mindset? Wipe the 21-day belief from your memory banks.

Instead of counting the days, practice with discipline toward a level of mastery, not a time frame. That’s more fun anyway and is more in line with a growth and success mindset. Make a difference in yourself by changing your mind about how you acquire your habits.

Make a difference in the world by challenging the next person you hear that repeats this myth.