I suppose one can fail in one's own language. I had had blood taken by an incompetent doctor at a hospital; doctors are notorious for being poor at this, my veins aren't very large, and I had two rather bruised arms by the time she'd finished. So I went to the nearby pub to cope with the trauma. It was empty, so I ended up making conversation with the landlady, and told her my story, ending with the remark that it was fortunate that I wasn't a drug addict, as I wasn't great with my hands and had narrow veins.
People who work in pubs don't often listen to actual sentences – they're just alert for key words, which evoke a specific response. They're not big on jokes, either, particularly ones involving drugs. I had a bit of sympathy because my story mentioned 'hospital', and most people going into a pub next to one have their tale of woe associated with it. But I had now forfeited it by admitting that I was a drug addict, and had only come into the place to shoot up in the toilet or corrupt the youth. I was younger then, though, and hadn't realised a fundamental truth about life.