Kelly gleans insights from Stanford University Professor BJ Fogg on the science of changing habits.

In the introduction to your book you say that there is a painful gap between what people want and what they do. Why is that?

“Oh, people really do want to change and improve their lives, but they don't know how to do it. They haven't been given a simple, realistic way of bringing new habits into their life. Instead, there's kind of this history of here's how you change and it uses willpower and you have to keep yourself motivated. That's the old way and that does not work very well. And, unfortunately, too often people believe that that's the only way to do it. It has to be painful. You have to find willpower. And that's not true at all. Tiny habits. I map out a simple way to do it that's actually fun.”

There is one tiny habit that you say is good for everybody.

“Yeah. There's only one habit that I've prescribed for everybody and it's the Maui habit. And that's as soon as your feet hit the floor in the morning, you say it's going to be a great day. And what happens is it just sets your day in the right direction. So it's a great habit to do. Tiny habits is all about what do you want to do and here's the method for making it a reality. But yes, I do prescribe the Maui habit.”

You say behaviors are like bicycles: they can look different, but the core mechanisms are the same: wheels, breaks and pedals. So is this true essentially of all behavior?

“All behaviors. So there are habits that people want to stop. People want to stop checking social media so much. So guess what? You remove the prompt or you remove your ability, you take the app off your phone or you reduce motivation. So that's one behavior. A different behavior might be you want to eat a healthy snack every day at three o'clock. So that's now creating a habit, but it still comes back. Motivation, ability and prompt - whatever behavior type it is it always comes back to those three things. And that's in tiny habits. I explained that in detail for the first time and that's one reason I'm so excited about sharing this work at last. A systematic, accurate, simple way of understanding behavior.”