You've just reminded me of my petty nag.
I was in a pub last year with my good lady of the time, and when we went to the bar somebody had let rip with the most foul-smell, acrid fart either of us had ever had the misfortune to smell. It was so bad, that had the culprit made himself known, the only course of action would have been to congratulate him on the smell he had given birth to.
How does this link in? Well, I suspect a relative of his must have been on my bus home tonight, and the b*****d let rip with at least 4 such farts, the first of which was WORSE than the one described above.
Is it wrong that I decided the blame lay with a man wearing a Celtic scarf?