Inside every senior citizen there is a junior one trying to get out. This alter ego leads a very private life, since its aspirations, such as to drive a racing car or dye its hair petunia, if yielded to, would make its better half look a fool. There is nothing, after all, so ridiculous as mutton behaving like lamb.
In the privacy of our homes, however, we can allow ourselves to be as young as we feel, which is far, far younger than anybody, surveying our sober and responsible-looking facades, would suspect. I am not speaking of childishness (in England it goes without saying that in every bedroom there is a battered teddy bear or a mouse or a Beatrix Potter ornament rescued from nursery days, and even, perhaps, a celluloid duck in the bathroom), but rather of our ''sweet and twenties.''
In this portion of our lives, according to our recollection, we were wildly attractive, amusing, and extremely versatile, able to sing both high and low, knowing the lyrics of all the latest songs, prone to give devastatingly funny imitations of celebrities, and dancing the night through if so required. That is our story, anyway, and this is the person we like to bring out of retirement when we are alone. This is the person we see in the mirror when we make famous faces into it . . . we have never forgotten we were once told we looked like Lauren Bacall . . . or perhaps it was Humphrey Bogart? When there is nobody to hear us we can still sing very nearly like Judy Garland or Perry Como, albeit in a slightly lower key; and if anybody plays ''Singin' in the Rain'' we can dance it almost as well as we used to, if not quite as well as Gene Kelly.
Dancing is, perhaps, a little dodgy. Not because we can no longer do it, but because it seems more difficult to stop. The other day, radio-inspired by a Viennese waltz played by a Viennese orchestra in Vienna - an irresistible combination - I began to circulate, solo and swooning with pleasure, in my sitting room. Being five feet, ten inches tall, and what is kindly termed Junoesque, I gathered momentum with extraordinary speed, and was soon whirling round like a runaway cyclone, ending up by crashing into a table covered in gewgaws. Few of which survived.
Recapturing one's youth does not necessitate going to places or hearing the sounds or smelling the smells of yesteryear, evocative though these may be. It only needs solitude. It only needs time to be oneself. Our prime of youth is never very far away: behind closed doors we are as silly (and of course as adorable) as ever we were.