A man went into a chemist's shop and said, 'I want some thing for a very bad headache.'
The chemist took a bottle from a shelf, held it under the man's nose and opened it.
The smell was so strong that tears came into the man's eyes and ran down his cheeks.
'What did you do that for?' he said angrily, as soon as he could get back his breath.
'But that medicine has cured your headache, hasn't ti? said the chemist.
'You fool,' said the man. 'It's my wife that has the headache, not me!'