Have you ever noticed that when asking for help to move a washing machine, put up shelves or assist in a similarly dull endeavour people take great care over their syntax. It's never "can you help me pick my nose?", it's always "are you free at the weekend?" - planting the germ of excitement in your mind (concert tickets perhaps?).
By the time you have cleared your diary and commenced speculation on the availability of back stage passes you realise that in reality you've agreed to run in a particularly nasty cross country race. As the light dawns you learn it's 15k long, hilly, muddy, a pain in the arse to get to and always freezing. Not only that, it's going to disrupt your diligently constructed training schedule and you're likely to come as near to last as first.
Having been ambushed, this saturday is now reserved for the Southern Counties Cross Country Championships at Parliament Hill in London. A hill named, depending on who you believe, for being occupied by troops sympathetic to parliament or because it's where Guy Fawkes used to go dogging on cold November evenings a few hundred years ago.
As always, a positive mindset is of vital importance when approaching any sort of race. I'm dreading it and it's going to be miserable.