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.

Through positive thinking and related approaches, we seek the safety and solid ground of certainty, of knowing how the future will turn out, of a time in the future when we'll be ceaselessly happy and never have to fear negative emotions again. But in chasing all that, we close down the very faculties that permit the happiness we crave.

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.

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.

True security lies in the unrestrained embrace of insecurity - in the recognition that we never really stand on solid ground, and never can.

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.

It is illuminating to note, here, how the daily rituals and working routines of prolific authors and artists - people who really do get a lot done - very rarely include techniques for 'getting motivated' or 'feeling inspired'. Quite the opposite: they tend to emphasise the mechanics of the working process, focusing not on generating the right mood, but on accomplishing certain physical actions, regardless of mood.