A few years ago, I had a day that was objectively good, but not perfect. My work had paid for me to get professional photos taken, but on the way there, I got a bad haircut. The photo session was fun, but I thought the photos looked terrible. On the way back, I got stuck in traffic. But get this: all of this was happening in sunny Miami; if I was somewhere else, I could be stuck in the dead of winter.

I should have just appreciated my good fortune – a day of being pampered in a tropical paradise. But instead, I broke down in tears. “I hate everyone and everything,” I sobbed to my husband while chugging from a goblet of wine. At the time, I had a tendency to do things like this – snatching dissatisfaction from the jaws of happiness. A performance review that was great, but not outstanding? Wine and whine. A beach vacation during which it rained? You guessed it.

To an outside observer, my life was excellent: I had a solid relationship, an interesting job as a journalist and a stable place to live. Through my job, I learned about a scientific personality test called the Big Five, and out of curiosity, I took it. The results showed that my particular combination of personality traits correlated with unhappiness and dysfunction. (Though, in fairness, my therapist or any of my friends could have probably could have told me this.) Personality traits are supposed to help you achieve your goals, but my traits were thwarting me; in particular, my high level of the personality trait neuroticism, which is associated with anxiety and depression, meant that when some calamity – unemployment or a health scare, for example – did inevitably strike, I crumbled more quickly than most.

“I used to think personality was permanent. Then I changed mine”