Gretchen Rubin

Happiness is a critical factor for work, and work is a critical factor for happiness. In one of those life-isn't-fair results, it turns out that the happy outperform the less happy. Happy people work more hours each week - and they work more in their free time, too.

A person with 'oppositional conversational style' is a person who, in conversation, disagrees with and corrects whatever you say. He or she may do this in a friendly way, or a belligerent way, but this person frames remarks in opposition to whatever you venture.

Nature is impersonal, awe-inspiring, elegant, eternal. It's geometrically perfect. It's tiny and gigantic. You can travel far to be in a beautiful natural setting, or you can observe it in your backyard - or, in my case, in the trees lining New York City sidewalks, or in the clouds above skyscrapers.

My mum and dad ran a family cafe in Sligo for 35 years and worked long hours. We grew up in a very hard-working family and had a lovely atmosphere, as we lived above the restaurant. It definitely made me want to work hard, whatever I chose to do. As the baby of seven kids, I was definitely a bit spoilt.