Peter walked out of the bathroom. With his dressing gown wrapped round him, he hobbled across the landing, wincing each time his feet found the carpet.
His seven year old son greeted him, ‘daddy, can we play football?’
Peter looked at his son, aghast, ‘no, Luke! My legs are killing me.’
Luke looked confused, ‘why?’
Peter rolled his eyes, ‘I’ve just run a half marathon, Luke. That’s why!’
Luke paused, ‘half a marathon? Why didn’t you finish it?’