A counting rhyme about the apostles and a miscount over Simon Peter
As a child I had a counting-out rhyme for memorising the apostles, but something in it troubled me: however I recited it, the count never came out right, and I kept ending up with 13 men. In time I even resigned myself to this, supposing that the odd man out was surely Judas. But in the end, having made the acquaintance of the actual text, I discovered that the discrepancy arose because Simon Peter is one man, not two, and everything finally added up. This happens with oral knowledge. It is rather like the business of pronouncing words you have only ever met on paper, but the other way round.
Illustration: The Descent of the Holy Spirit upon the Apostles, Giotto, from the Scrovegni Chapel in Padua