Stories get bigger with the telling, especially when recounted by people with imagination. They are embroidered with elaborate curlicues and populated with more interesting characters. And not just for the benefit of the listener, either. Pretty soon, they pass into one's own internal mythology - an irretrievably entangled mass of the real and the magical which is very unlikely ever to be challenged.
Unless, that is, you are a politician. We have come to the point in the electoral cycle when Des O'Connor's researchers telephone Tony Blair's office and invite him to submit himself to one of Des's rigorous policy examinations, sandwiched between a ventriloquist and Boyzone.
This is also the season for the three party leaders to be quizzed by the readers of Good Housekeeping (p54, just before "planning the perfect party" - so John Major should read on).
As a consequence of these appearances, we have learned two things this week, only to have them contested. The first (vouchsafed to Mr O'Connor) was the great Blair stowaway story, in which the adolescent Tone skips the train about to carry him back to his stuffy public school and attempts to fly off in a plane from Newcastle airport bound - he thinks - for the Bahamas.
No sooner had the show been recorded than the delighted Desniks circulated the world with a press release; the Daily Mail delved deep and discovered that there were no planes flying from Newcastle to the Bahamas in that decade (or, indeed, any other), and that Jersey was the most exotic destination on offer. Even a Scots public schoolboy of the late 1960s would have had difficulty in confusing the two. Er, perhaps.
Conservative Central office were said to be "cock-a-hoop" about this Blair gaffe, until the second discovery of the week was also thrown into doubt.
This was Mr Major's revelation that he calls his wife Norma his "little grub". Taxed with this while visiting Northern Ireland, she said "we don't have nicknames for each other. What rubbish!"
We do not yet know whether Labour is "cock-a-hoop" at Mrs Major's repudiation of her husband, but it's quite probable that they are. (Incidentally, also in Good Housekeeping, Paddy Ashdown is revealed as having locked his kindergarten teacher in a cupboard. So far, she has not contradicted him. But then, knowing Mr Ashdown, she's probably still there).
Two things should concern us here. The first is the light these stories shed on our leaders. Did T. Blair say "Bahamas" because he thought it sounded more dare-devil (ie, he's a dissembler), or because - long ago - that is what entered his own mythology (ie, he's like the rest of us)?
Do John and Norma disagree about little grub because she's appalled by the nickname and is fibbing (incidentally, what nickname does she give him? Tiger, perhaps?) or - intriguingly - he has confused her with someone else (a previous girlfriend, possibly)?
I think that we ought to conclude that our political leaders are made of much the same clay as us; it's just that they almost always get found out. But should we also be worried that political discourse in this country is being debased by this concentration on trivia?
Do we agree with yesterday's Times editorial which argued - with the pomposity for which that publication is famed - "it would be desirable if politicians refrained from telling the voters so much about the journeys they have made in the past and so little about where they propose to take the country in the future"? This is the same publication that (on page 2) has an entire article devoted to the Bahamas/Little Grub story.
Maybe we should. Perhaps it would be best for politicians on Des O'Connor's show to reprove their genial host for his interest in things personal, reminding him that what viewers really care about is Labour's training policies. It might even keep the pop stars away from politics.