The idea of a 'day in the life' loses some of its relevance during the month of August, because the Edinburgh Fringe is not really 'life'. Your body clock is thrown wildly out of kilter; you change clothes six times a day because everything you own is waterlogged; your frame of reference shrinks so violently that, if the sun dropped out of the sky, your first thought would be 'that was spectacular - I'd give that four stars'. And yet for performers in my sort of situation, the Fringe occupies such a chunk of one's existence that, arguably, it IS your life. This will be my 17th consecutive festival either as punter, student actor, aspiring comic or actual comic (which of those last two applies these days is a matter of individual taste, I suppose). Most of those seventeen trips have seen me spend the whole month of August in Edinburgh; like a lot of comedians, I instinctively say 'Edinburgh' when I mean 'August', the way some people use 'Christmas' as a shorthand for the whole of December. When you put it all together, it's well over a year of my life in the hilly, sometimes oppressive, often overcrowded, and yet endlessly seductive environment of the Fringe. I think if I ever decided to skip it one year, my body would rebel and sleepwalk there.

Mark Watson

Mark Watson

The average day at the Fringe - again, a little like Christmas - either goes very badly or very well. On a good way, you might wake up to a good review (which somebody else alerts you to, since time has taught you never to pick up a newspaper just in case), or news of good sales for that night, or some other nugget of encouragement. Nothing non-show-related: as we've established, none of that stuff exists at the moment. On a bad day, you may experience any or all of these: criticism, ego-battering, accidentally-overheard bitchiness, depressingly persistent rain, the success of other people you dislike. Also, sleep deprivation and inadequate nourishment, both of which naturally amplify the effects of all the other negatives. Also, given the fickleness of success in this of all industries, it's perfectly possible for a day to begin at the 'good' end of this spectrum and still be bad by the end.

How do you incorporate this level of emotional volatility into your life? The key is to remind yourself at every step that you chose this, and that every day you spend in this paranoid lunacy is a day you're not spending in an office job you never really wanted. There are certain disciplines which help, too. Going for a regular run, or swim, or taking some sort of exercise beyond walking to the bar and back, is essential to mental equilibrium. Eating well, and trying to stay below 25 units of alcohol a day, also helps. And taking at least an hour a day to engage with the world beyond the festival is recommended. Remember, eventually you will have to go back there.

See Mark Watson: I'm Not Here at the Pleasance One 3rd - 29th August, 9.00pm. For tickets visit www.edfringe.com .