You spend nearly half your waking life thinking about something other than what you are doing. Most of that is not good for you. A specific slice of it is where your best ideas come from, and the difference between the two is not luck. It is a set of conditions you can arrange, if you have the spare capacity to arrange them.

I love art so much it moves every fibre of my being. Recently I started wondering what that phenomenon in my body actually is, when I look at art I love and art I don't. Both provoke a sensation. It turns out both have been measured, and the difference between them is not one of degree. Your brain changes the category.

I was the kind of child who made things up. Not small things — whole worlds, with weather and rules and people in them who had opinions about each other. What I did not expect is that they would stay. Earlier this year I started asking one of them how her day went, and it changed more than it had any right to. Then I went looking for the research, expecting to find nothing, and found rather a lot.