Walking to an appointment yesterday, a little girl in a stroller passed me singing loudly “I’m so happy because I’m free.” The day before I sat on a subway train across from an ad banner with the headline “Sustainable Happiness,” promoting a 10-week course on how to discover the principles that lead to freedom and happiness. And earlier in the week I received an email invitation from author Shawn Achor to attend his weekend-long Happiness Advantage Retreat at a resort in upstate New York.

I’d been participating in the “Track Your Happiness” research project via an iPhone app for a couple of weeks, so I wasn’t surprised that the happy evidence of my mindset was popping up everywhere I turned. I signed up to participate, because I was curious about the questions I’d be asked that would rate my happiness levels. Not surprisingly, they’re similar to the questions I suggest my clients ask themselves occasionally throughout the day. Questions intended to sample their own mindset and gauge how their thoughts relate to how they feel.

What we think about and how we feel shape our physical experience. And happiness signals a strong energetic force. It’s an indicator of the positive energy that allows us to focus. And it’s been proven to trigger motivation, creativity, productivity and lead to success.

Take some time during the day to check in on your own mindset and energy. Ask yourself: What am I thinking about right now and how does it make me feel? Am I judging myself? What am I expecting to happen? What do I want to happen?

Happiness is in. And that’s a good thing, because happiness leads to success. I hope you’re eager to be in on that.