It doesn’t take 21 days to wire in a habit, says psychologist BJ Fogg. Sometimes, all you need is a shot of positive feeling and emotion, a dose of celebration. Celebrating is a great way to reinforce small changes — and pave the way for big successes.

Feel like you start the new year ready to reinvent your life, only to find that, a month later, you’ve given up on everything and are living a life that’s totally indistinguishable from last year?

Psychologist Susan David explains why a simple switch from “I must go to the gym three times a week” to “I want to go to the gym three times a week” can put your goal within reach.