A humbling fact about the happiness project is the many of the ideas that have made the biggest difference in my life are so…simple.

Take, for example, one of my Twelve Commandments: “Identify the problem.”

There have been so many instances where I’ve been unhappy with a situation, but didn’t take the trouble to analyze what was bothering me—and therefore, couldn’t take steps to fix it. Once I identified the problem, I saw the solution.

Here’s a humiliatingly obvious example.

I’m someone who is always, always cold. I’m often very uncomfortable in places that other people find perfectly warm. I have to be careful when I change the Little Girl’s diaper, because my hands are always icy cold. I’ve been known to wear a wool hat indoors.

One of the worst situations is a dinner where everyone is dressed up. The room is set to be a comfortable temperature for men wearing full suits, and I’m usually wearing a dress.

Finally, I thought – “Identify the problem.” I’m cold. How could I be warmer? Well, I could dress more warmly. How do I do that, if I’m wearing a sleeveless dress? I could wear a bodysuit. So I went to a lingerie store and bought a bodysuit (also fulfilling my resolution to “spent money to further my goals”). It’s astonishing how much warmth a bodysuit provides, without adding any bulk.

For the last week, New York City has been having a spell of extraordinarily cold weather. Instead of complaining (well, truth be told, in addition to complaining), I’ve taken steps to dress more warmly. I wear long underwear, two sets of socks, and my heaviest sweaters. This isn’t rocket science, but a few years ago, I doubt whether I would have thought to wear long underwear during a regular work day, no matter how cold it was. It just wouldn’t have occurred to me.

Every time I’ve managed to “identify the problem,” I’ve been able to arrive at least a partial solution. Why I need to make a special effort to notice a problem that’s bugging me, I don’t know—but following this rule has made a big difference.

From 2006 through 2014, as she wrote The Happiness Project and Happier at Home, Gretchen chronicled her thoughts, observations, and discoveries on The Happiness Project Blog.