Even when men do more housework and child care, a lot of times it's still women in charge, delegating, so you have all that noise in your brain. You're on a bike ride or picnic with your family, and it looks like leisure, but on the inside you are keeping track of everybody's emotional temperature, and did I pack this, what are the directions, how much time are we going to be here, do we have anything for dinner? It's like a toilet running all the time.

I have trashed the to-do list. To help my brain...

I was afraid that I would find out that I didn't work hard, that I wasn't a very good mother. I was feeling so inadequate in everything I did. I was afraid that I was going to come out being this crazy, disorganized, neurotic person. So it was revelatory that I worked more than 50 hours a week and I still spent a tonne of time with my kids. It was like, "Why do I feel one way when the reality is so different?"

If you had the perception that you are very stressed out then your grey matter was fully 20 per cent smaller in volume than people who did not have that same feeling. This is the grey matter in your prefrontal cortex: It controls thinking, learning, planning, decision-making. That matters because when we are feeling more stressed, that is when we are at our most vulnerable in our inability to think our way out of it.

The more armed we are with information about the seduction of technology, the more we can build systems to better deal with it. I had no idea that I got a hit of dopamine, which is the pleasure hormone that also governs addiction, every time that little email bing goes off.

Even when men do more housework and child care, a lot of times it's still women in charge, delegating, so you have all that noise in your brain. You're on a bike ride or picnic with your family, and it looks like leisure, but on the inside you are keeping track of everybody's emotional temperature, and did I pack this, what are the directions, how much time are we going to be here, do we have anything for dinner? It's like a toilet running all the time.

Busyness has become such a social value that we will even create it, we will create that sense of breathlessness because we think that's how we show status and importance. That is a really interesting and troubling finding. We've taken this notion of hard work to a crazy degree.