> 'If you look at what people actually do to be happier, it seems nearly everyone tries to change the external facts: we try to become richer, thinner, more successful, to find a better house in a nicer area, and so on. A few of us think about trying to spend less time working, and more time on hobbies or with friends and family. Almost no one thinks about actively retraining the way they think. In fact, I don’t think this last idea even crosses most of our minds.'
You might be new to this because you've just started your PhD, but that doesn't mean everyone else is too.