Ask yourself whether you are happy', observed the philosopher John Stuart Mill, 'and you cease to be so.' At best, it would appear, happiness can only be glimpsed out of the corner of an eye, not stared at directly.

Ceaseless optimism about the future only makes for a greater shock when things go wrong; by fighting to maintain only positive beliefs about the future, the positive thinker ends up being less prepared, and more acutely distressed, when things eventually happen that he can't persuade himself to believe are good.

What made Leonardo da Vinci, Thomas Edison and Albert Einstein such creative geniuses? It wasn't reading books or watching YouTube talks about How To Be More Creative, that's for sure... If startling insights could be systematically arrived at, they wouldn't be startling. The best you can do is to create a conducive environment: put in the hours; take time to daydream; avoid mind-corroding substances.

The routines of almost all famous writers, from Charles Darwin to John Grisham, similarly emphasise specific starting times, or number of hours worked, or words written. Such rituals provide a structure to work in, whether or not the feeling of motivation or inspiration happens to be present. They let people work alongside negative or positive emotions, instead of getting distracted by the effort of cultivating only positive ones. ‘Inspiration is for amateurs,’ the artist Chuck Close once memorably observed. ‘The rest of us just show up and get to work.

Uncertainty is where things happen. It is where the opportunities - for success, for happiness, for really living - are waiting.

Ask yourself whether you are happy', observed the philosopher John Stuart Mill, 'and you cease to be so.' At best, it would appear, happiness can only be glimpsed out of the corner of an eye, not stared at directly.

The real trick to producing great work isn't to find ways to eliminate the edgy, nervous feeling that you might be swimming out of your depth. Instead, it's to remember that everyone else is feeling it, too. We're all in deep water. Which is fine: it's by far the most exciting place to be.