Something odd happened to me this week.

I was in Dallas for my book tour for Better Than Before, I was in the gym, walking on the treadmill, when suddenly I felt something shift in my personality.

The experience lasted about twenty seconds.

It was like a dial turned inside me. Or like the chips of glass inside a kaleidoscope made a new pattern.

I was still myself, but somehow in different proportions. I felt, for that moment, what it would be like to be…different. More light-hearted, more easy-going.

One fact about me is that I’m intense. There’s a relentlessness to my nature. And I don’t mind that.

My discipline is my freedom. @gretchenrubin (Click to Tweet!)

My sister Elizabeth tells me that I’d make a good monk. I’m an Upholder, and I love being an Upholder! Even though I recognize the downsides to it.

But for just a minute, for some reason, I felt like a different person. Then I snapped back to normal.

Something like this has happened to me once before. A few years ago, I was walking down Lexington Avenue, and suddenly I felt all my ambition vanish. It was as if I’d been carrying a heavy backpack for decades, and suddenly it slid off my back. I’d never consciously realized it before, but I have a voice in my head constantly saying, “Did you…?” “Should you…?” “Could you…?” For a moment, it was shut off, and then it returned.

And that was what I felt, this morning. I experienced myself as if I were just a little bit different. It was odd, and exhilarating, and a little sad. It would be fun to be less relentless!

And yet I must Be Gretchen.

This is the music that was playing when it happened — Rachel Portman’s Main Theme from the soundtrack of the movie Chocolat. I guess it set off some kind of unexpected response.

Also, for a writer, having a new book out makes everything feel very heightened, so I’m sure that also contributed to it.

Have you ever had an experience like this? It was very odd. For a moment, I was someone different. Not very different, but different nevertheless.

Gretchen Rubin is the author of the #1 New York Times Bestseller The Happiness Project—an account of the year she spent test-driving the wisdom of the ages, current scientific studies, and lessons from popular culture about how to be happier—and the recently released Happier at Home and Better Than Before. On her popular blog, The Happiness Project, she reports on her daily adventures in the pursuit of happiness. For more doses of happiness and other happenings, follow Gretchen on Facebook and Twitter.

Image courtesy of Nuno Silva.