Martha walked into the garden shop and asked for a houseplant she couldn’t kill.
The assistant offered her a cactus.
‘I drowned my last one,’ Martha said.
‘What about a plastic plant?’
‘My husband dusted ours so hard that the leaves fell off.’
The assistant thought for a moment, then put an empty terracotta pot on the counter.
‘You’re selling me a pot?’ Martha asked.
‘It comes with a lifetime guarantee,’ the assistant said.
‘Against what?’
‘If you manage to kill it,’ the assistant replied, ‘I’ll give you your money back.’