The symptoms? Talking about the joy of album cover design to people half my age who don't know what an LP is - and being met with a sea of glazed expressions. Or mentioning the Golden Rules of Direct Marketing to younger colleagues who didn't even know DM had rules, let alone golden ones.
So you can just imagine the incredulity of a former colleague when asked about a Johnson Box. Was it American slang for a toilet? No, that's the john. How about the collective works of Dr Samuel Johnson as a boxed set? No.
You're a reader of Marketing Direct, so I have no doubt you'll know that I am referring to the small box of text, first created by Frank Johnson, which sits above the salutation on a letter as a preface to the argument that follows.
Johnson, a copywriter in 1940s New York, understood how people read letters, and how to get their attention. He innovated with such flourishes as indented paragraphs and a PS, and always finished a page with a broken sentence to encourage readers to turn the page. And he was a master of what is now a dying art form - the four-page letter. What made him a master was his capacity to innovate with form, as well as his exquisite use of language.
Witness this excerpt from a letter in which he invited readers to remember "lying in bed as a child and hearing, far off, the whistle of a steam locomotive as it pounded through the night. The wail was hoarse, mournful, inimitable. And once upon a time it was a siren song for any youngster". Read copy like that recently? Didn't think so.
Actually, I'm being unkind. There are still talented writers capable of holding your attention for several pages. I grew up under the tutelage of one, George Smith. I admired the long-form press ads written by Indra Sinha. And I have another such craftsman as a business partner, Paul Kitcatt.
But if the exponents of this art are in short supply, so is the appreciation of its beauty. In 北京赛车pk10 recently, two advertising creatives lambasted a letter for its length. On what grounds? They didn't have any. A letter should be as long as it needs to be. Just as a headline should not have a prescribed length. Or an email for that matter. If it's compelling, length is irrelevant.
We could do well to learn from Johnson. As well as Mssrs Ogilvy, Bernbach, Bird, Smith and others. The wisdom of our elders, I think it's rather unfashionably called.
Marc Nohr is the managing partner of Kitcatt Nohr Alexander Shaw.