Only when a neighbour phoned one of the schools to compliment the headteacher on the two polite pupils who had been at her door - "and what were they collecting for anyway?" - did the scam come to light. No doubt they would be able to provide a plausible excuse, if asked.
My own imagination was tested by a recent pupil whose review of personal reading had not, to my knowledge, yet seen the light of day. When pressed he offered the not very original excuse that his book and all his notes had disappeared around Christmas. Sceptical of such hackneyed deception I looked quizzical. The interrogative eyebrow arched.
Protesting his innocence, the words poured out - "a crowd of us were at an overnight at Laura's house and I left my bag". I asked why he hadn't returned to claim his belongings. "I did but it was two weeks later and the house had been sold."
Another senior pupil sought me out, late one morning, wanting to "drop" physics. His agitation increased asmy reluctance became clear until it transpired that the afternoon's impending Higher Still assessment was creating most of his kinetic energy. By comparison, the telephone response to a book delivery delay seemed positively wholesome. "Ma computer's went wonky" said the girl artlessly, putting her on a par with the homework-free child who gently explained "nobody studies up ma bit".
Little wonder Only An Excuse is such a popular programme with teenagers. However, it was an adult who provided my least convincing excuse experience. Some years ago a Scotvec moderator from a remarkably distant centre, say Fort William, arranged to come to Glasgow to check a current geography module. For some internal reason the date changed and I wrote to let him know.
When the original date came round I was summoned from my class by the message that the moderator had arrived and wondered where he was to go. I explained that I'd sent him a letter, and apologised for his journey. He said he'd never received it, opened his document case for his diary to make a new date, and there - on the top of everything else - lay my letter. I pointed it out to him whereupon he said, with impeccable sang-froid, "Oh that letter".
Perhaps he merely wanted an awayday in Glasgow.